chore: update version values

confirmed that macos works.

.circleci/config.yml

@@ -12,9 +12,32 @@ jobs:
           command: |
               g++ --version
               cd tests/
-              g++ -std=c++11 -O2 -Wall -Wextra -Werror -I../ check_toml_test.cpp -o check_toml_test
+              g++ -std=c++11 -O2 -Wall -Wextra -Werror -DTOML11_DISALLOW_HETEROGENEOUS_ARRAYS -I../ check_toml_test.cpp -o check_toml_test
               go get github.com/BurntSushi/toml-test
               $GOPATH/bin/toml-test ./check_toml_test
+  test_serialization:
+    docker:
+      - image: circleci/buildpack-deps:bionic
+    steps:
+      - checkout
+      - run:
+          command: |
+              g++ --version
+              cd tests/
+              g++ -std=c++11 -O2 -Wall -Wextra -Wpedantic -Werror -DTOML11_DISALLOW_HETEROGENEOUS_ARRAYS -I../ check_serialization.cpp -o check_serialization
+              git clone https://github.com/BurntSushi/toml-test.git
+              cp check_serialization toml-test/tests/valid
+              cd toml-test/tests/valid
+              for f in $(ls ./*.toml);
+                do echo "==> ${f}";
+                cat ${f};
+                echo "---------------------------------------";
+                ./check_serialization ${f};
+                if [ $? -ne 0 ] ; then
+                  exit 1
+                fi
+                echo "=======================================";
+              done
   output_result:
     docker:
       - image: circleci/buildpack-deps:bionic
@@ -24,7 +47,7 @@ jobs:
           command: |
               g++ --version
               cd tests/
-              g++ -std=c++11 -O2 -Wall -Wextra -Werror -I../ check.cpp -o check
+              g++ -std=c++11 -O2 -Wall -Wextra -Wpedantic -Werror -DTOML11_DISALLOW_HETEROGENEOUS_ARRAYS -I../ check.cpp -o check
               git clone https://github.com/BurntSushi/toml-test.git
               cp check toml-test/tests/invalid
               cp check toml-test/tests/valid
@@ -56,4 +79,5 @@ workflows:
   test:
     jobs:
       - test_suite
+      - test_serialization
       - output_result

.github/workflows/main.yml

@@ -0,0 +1,151 @@
+name: build
+
+on: [push, pull_request]
+
+jobs:
+  build-linux-gcc:
+    runs-on: Ubuntu-18.04
+    strategy:
+      matrix:
+        # g++-4.8 and 4.9 are tested on Travis.CI.
+        compiler: ['g++-9', 'g++-8', 'g++-7', 'g++-6', 'g++-5']
+        standard: ['11', '14', '17', '20']
+        exclude:
+            - {compiler: 'g++-5', standard: '17'}
+            - {compiler: 'g++-6', standard: '17'}
+            - {compiler: 'g++-5', standard: '20'}
+            - {compiler: 'g++-6', standard: '20'}
+            - {compiler: 'g++-7', standard: '20'}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          submodules: true
+      - name: Install
+        run: |
+            sudo apt-add-repository ppa:mhier/libboost-latest
+            sudo apt-get update
+            sudo apt-get install boost1.70
+            if [[ "${{ matrix.compiler }}" == "g++-6" || "${{ matrix.compiler }}" == "g++-5" ]] ; then
+                sudo apt-add-repository ppa:ubuntu-toolchain-r/test
+                sudo apt-get update
+                sudo apt-get install ${{ matrix.compiler }}
+            fi
+      - name: Configure
+        run: |
+            mkdir build && cd build
+            if [[ "${{ matrix.compiler }}" == "g++-8" && ( "${{ matrix.standard }}" == "17" || "${{ matrix.standard }}" == "20" ) ]] ; then
+                cmake .. -Dtoml11_BUILD_TEST=ON -DCMAKE_CXX_COMPILER=${{ matrix.compiler }} -DCMAKE_CXX_STANDARD=${{ matrix.standard }} -DTOML11_REQUIRE_FILESYSTEM_LIBRARY=ON
+            else
+                cmake .. -Dtoml11_BUILD_TEST=ON -DCMAKE_CXX_COMPILER=${{ matrix.compiler }} -DCMAKE_CXX_STANDARD=${{ matrix.standard }}
+            fi
+      - name: Build
+        run: |
+            cd build && cmake --build .
+      - name: Test
+        run: |
+            cd build && ctest --output-on-failure
+  build-linux-clang:
+    runs-on: Ubuntu-18.04
+    strategy:
+      matrix:
+        compiler: ['10', '9', '8', '7', '6.0', '5.0', '4.0', '3.9']
+        standard: ['11', '14', '17', '20']
+        exclude:
+            - {compiler: '3.9', standard: '17'}
+            - {compiler: '4.0', standard: '17'}
+            - {compiler: '5.0', standard: '17'}
+            - {compiler: '3.9', standard: '20'}
+            - {compiler: '4.0', standard: '20'}
+            - {compiler: '5.0', standard: '20'}
+            - {compiler: '6.0', standard: '20'}
+            - {compiler: '7',   standard: '20'}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          submodules: true
+      - name: Install
+        run: |
+            sudo apt-add-repository ppa:mhier/libboost-latest
+            sudo apt-get update
+            sudo apt-get install boost1.70
+            if [[ "${{ matrix.compiler }}" != "6" && "${{ matrix.compiler }}" != "8" && "${{ matrix.compiler }}" != "9" ]] ; then
+                sudo apt-add-repository ppa:ubuntu-toolchain-r/test
+                sudo apt-get update
+                sudo apt-get install clang-${{ matrix.compiler }}
+            fi
+      - name: Configure
+        run: |
+            mkdir build && cd build
+            cmake .. -Dtoml11_BUILD_TEST=ON -DCMAKE_C_COMPILER=clang-${{ matrix.compiler }} -DCMAKE_CXX_COMPILER=clang++-${{ matrix.compiler }} -DCMAKE_CXX_STANDARD=${{ matrix.standard }}
+      - name: Build
+        run: |
+            cd build && cmake --build .
+      - name: Test
+        run: |
+            cd build && ctest --output-on-failure
+
+  build-osx:
+    runs-on: macos-10.15
+    strategy:
+      matrix:
+        standard: ['11', '14', '17', '20']
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          submodules: true
+      - name: Install
+        run: |
+            brew install boost
+      - name: Configure
+        run: |
+            mkdir build && cd build
+            cmake .. -Dtoml11_BUILD_TEST=ON -DCMAKE_CXX_STANDARD=${{ matrix.standard }}
+      - name: Build
+        run: |
+            cd build && cmake --build .
+      - name: Test
+        run: |
+            cd build && ctest --output-on-failure
+
+  build-windows-msvc:
+    runs-on: windows-2019
+    strategy:
+      matrix:
+        standard: ['11', '14', '17', '20']
+        config: ['Release', 'Debug']
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          submodules: true
+      - name: Install
+        run: |
+            (New-Object System.Net.WebClient).DownloadFile("https://github.com/actions/boost-versions/releases/download/1.72.0-20200608.4/boost-1.72.0-win32-msvc14.2-x86_64.tar.gz", "$env:TEMP\\boost.tar.gz")
+            7z.exe x "$env:TEMP\\boost.tar.gz" -o"$env:TEMP\\boostArchive" -y | Out-Null
+            7z.exe x "$env:TEMP\\boostArchive" -o"$env:TEMP\\boost" -y | Out-Null
+            Push-Location -Path "$env:TEMP\\boost"
+            Invoke-Expression .\\setup.ps1
+      - uses: ilammy/msvc-dev-cmd@v1
+      - name: Configure
+        shell: cmd
+        run: |
+            file --mime-encoding tests/test_literals.cpp
+            mkdir build
+            cd build
+            cmake ../ -G "NMake Makefiles" -Dtoml11_BUILD_TEST=ON -DCMAKE_CXX_STANDARD=${{ matrix.standard }} -DBoost_NO_BOOST_CMAKE=ON -DBOOST_ROOT="C:\\hostedtoolcache\\windows\\Boost\\1.72.0\\x86_64"
+      - name: Build
+        working-directory: ./build
+        run: |
+            cmake --build . --config "${{ matrix.config }}"
+      - name: Test
+        working-directory: ./build
+        run: |
+            ./tests/test_literals --log_level=all
+            file --mime-encoding tests/toml/tests/example.toml
+            file --mime-encoding tests/toml/tests/fruit.toml
+            file --mime-encoding tests/toml/tests/hard_example.toml
+            file --mime-encoding tests/toml/tests/hard_example_unicode.toml
+            ctest --build-config "${{ matrix.config }}" --output-on-failure

.travis.yml

@@ -2,6 +2,30 @@ dist: trusty
 
 matrix:
   include:
+  - os: linux
+    language: cpp
+    compiler: gcc
+    env: COMPILER="g++-4.8" CXX_STANDARD=11
+    addons:
+      apt:
+        sources:
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
+        packages:
+        - g++-4.8
+        - boost1.70
+  - os: linux
+    language: cpp
+    compiler: gcc
+    env: COMPILER="g++-4.9" CXX_STANDARD=11
+    addons:
+      apt:
+        sources:
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
+        packages:
+        - g++-4.9
+        - boost1.70
   - os: linux
     language: cpp
     compiler: gcc
@@ -9,10 +33,11 @@ matrix:
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
         packages:
         - g++-5
-        - libboost-all-dev
+        - boost1.70
   - os: linux
     language: cpp
     compiler: gcc
@@ -20,10 +45,11 @@ matrix:
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
         packages:
         - g++-6
-        - libboost-all-dev
+        - boost1.70
   - os: linux
     language: cpp
     compiler: gcc
@@ -31,10 +57,11 @@ matrix:
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
         packages:
         - g++-7
-        - libboost-all-dev
+        - boost1.70
   - os: linux
     language: cpp
     compiler: gcc
@@ -42,33 +69,73 @@ matrix:
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
         packages:
         - g++-8
-        - libboost-all-dev
+        - boost1.70
   - os: linux
     language: cpp
     compiler: gcc
-    env: COMPILER="g++-8" CXX_STANDARD=17
+    env: COMPILER="g++-8" CXX_STANDARD=11 TOML_HEAD=ON
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
         packages:
         - g++-8
-        - libboost-all-dev
+        - boost1.70
+  - os: linux
+    language: cpp
+    compiler: gcc
+    env: COMPILER="g++-8" CXX_STANDARD=14
+    addons:
+      apt:
+        sources:
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
+        packages:
+        - g++-8
+        - boost1.70
+  - os: linux
+    language: cpp
+    compiler: gcc
+    env: COMPILER="g++-8" CXX_STANDARD=17 REQUIRE_FILESYSTEM_LIBRARY=ON
+    addons:
+      apt:
+        sources:
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
+        packages:
+        - g++-8
+        - boost1.70
+  - os: linux
+    language: cpp
+    compiler: gcc
+    env: COMPILER="g++-8" CXX_STANDARD=17 TOML_HEAD=ON REQUIRE_FILESYSTEM_LIBRARY=ON
+    addons:
+      apt:
+        sources:
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
+        packages:
+        - g++-8
+        - boost1.70
   - os: linux
     language: cpp
     compiler: clang
-    env: COMPILER="clang++-3.7" CXX_STANDARD=11
+    env: COMPILER="clang++-3.9" CXX_STANDARD=11
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
-        - llvm-toolchain-precise-3.7
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
+        - llvm-toolchain-trusty-3.9
         packages:
-        - clang-3.7
-        - libboost-all-dev
+        - g++-8
+        - clang-3.9
+        - boost1.70
   - os: linux
     language: cpp
     compiler: clang
@@ -76,11 +143,13 @@ matrix:
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
         - llvm-toolchain-trusty-4.0
         packages:
+        - g++-8
         - clang-4.0
-        - libboost-all-dev
+        - boost1.70
   - os: linux
     language: cpp
     compiler: clang
@@ -88,11 +157,13 @@ matrix:
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
         - llvm-toolchain-trusty-5.0
         packages:
+        - g++-8
         - clang-5.0
-        - libboost-all-dev
+        - boost1.70
   - os: linux
     language: cpp
     compiler: clang
@@ -100,11 +171,13 @@ matrix:
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
         - llvm-toolchain-trusty-6.0
         packages:
+        - g++-8
         - clang-6.0
-        - libboost-all-dev
+        - boost1.70
   - os: linux
     language: cpp
     compiler: clang
@@ -112,11 +185,13 @@ matrix:
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
         - llvm-toolchain-trusty-7
         packages:
+        - g++-8
         - clang-7
-        - libboost-all-dev
+        - boost1.70
   - os: linux
     language: cpp
     compiler: clang
@@ -124,43 +199,139 @@ matrix:
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
         - llvm-toolchain-trusty-8
         packages:
+        - g++-8
         - clang-8
-        - libboost-all-dev
+        - boost1.70
   - os: linux
     language: cpp
     compiler: clang
-    env: COMPILER="clang++-8" CXX_STANDARD=17
+    env: COMPILER="clang++-8" CXX_STANDARD=11 TOML_HEAD=ON
     addons:
       apt:
         sources:
-        - ubuntu-toolchain-r-test
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
+        - llvm-toolchain-trusty-8
+        packages:
+        - g++-8
+        - clang-8
+        - boost1.70
+  - os: linux
+    language: cpp
+    compiler: clang
+    env: COMPILER="clang++-8" CXX_STANDARD=14
+    addons:
+      apt:
+        sources:
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
         - llvm-toolchain-trusty-8
         packages:
         - clang-8
         - g++-8
-        - libboost-all-dev
+        - boost1.70
+  - os: linux
+    language: cpp
+    compiler: clang
+    env: COMPILER="clang++-8" CXX_STANDARD=17 REQUIRE_FILESYSTEM_LIBRARY=ON
+    addons:
+      apt:
+        sources:
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
+        - llvm-toolchain-trusty-8
+        packages:
+        - clang-8
+        - g++-8
+        - boost1.70
+  - os: linux
+    language: cpp
+    compiler: clang
+    env: COMPILER="clang++-8" CXX_STANDARD=17 TOML_HEAD=ON REQUIRE_FILESYSTEM_LIBRARY=ON
+    addons:
+      apt:
+        sources:
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
+        - llvm-toolchain-trusty-8
+        packages:
+        - clang-8
+        - g++-8
+        - boost1.70
+  - os: linux
+    language: cpp
+    compiler: clang
+    env: COMPILER="clang++-8" CXX_STANDARD=11 WITH_ASAN=ON
+    addons:
+      apt:
+        sources:
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
+        - llvm-toolchain-trusty-8
+        packages:
+        - clang-8
+        - g++-8
+        - boost1.70
+  - os: linux
+    language: cpp
+    compiler: clang
+    env: COMPILER="clang++-8" CXX_STANDARD=11 WITH_UBSAN=ON
+    addons:
+      apt:
+        sources:
+        - sourceline: 'ppa:ubuntu-toolchain-r/test'
+        - sourceline: 'ppa:mhier/libboost-latest'
+        - llvm-toolchain-trusty-8
+        packages:
+        - clang-8
+        - g++-8
+        - boost1.70
   - os: osx
     language: cpp
     compiler: clang
-    env: CXX_STANDARD=11
 
 script:
 - |
   if [[ "${TRAVIS_OS_NAME}" == "linux" ]]; then
     mkdir -p cmake
-    travis_retry wget "https://cmake.org/files/v3.11/cmake-3.11.2-Linux-x86_64.tar.gz"
-    tar xf cmake-3.11.2-Linux-x86_64.tar.gz -C cmake --strip-components=1
+    travis_retry wget "https://github.com/Kitware/CMake/releases/download/v3.14.5/cmake-3.14.5-Linux-x86_64.tar.gz"
+    tar xf cmake-3.14.5-Linux-x86_64.tar.gz -C cmake --strip-components=1
     export PATH=${TRAVIS_BUILD_DIR}/cmake/bin:${PATH}
-  else
-    brew upgrade cmake
   fi
+- |
+  if [[ "${CXX_STANDARD}" == "" ]]; then
+      export CXX_STANDARD="11"
+  fi
+- |
+  if [[ "${TOML_HEAD}" != "ON" ]]; then
+    export TOML_HEAD="OFF"
+  fi
+- echo "TOML_HEAD = ${TOML_HEAD}"
+- |
+  if [[ "${WITH_ASAN}" != "ON" ]]; then
+    export WITH_ASAN="OFF"
+  fi
+- echo "WITH_ASAN = ${WITH_ASAN}"
+- |
+  if [[ "${WITH_UBSAN}" != "ON" ]]; then
+    export WITH_UBSAN="OFF"
+  fi
+- echo "WITH_UBSAN = ${WITH_UBSAN}"
+- echo "REQUIRE_FILESYSTEM_LIBRARY = ${REQUIRE_FILESYSTEM_LIBRARY}"
+- |
+  if [[ "${REQUIRE_FILESYSTEM_LIBRARY}" != "ON" ]]; then
+    export REQUIRE_FILESYSTEM_LIBRARY="OFF"
+  fi
+- echo "REQUIRE_FILESYSTEM_LIBRARY = ${REQUIRE_FILESYSTEM_LIBRARY}"
 - cmake --version
 - mkdir build
 - cd build
-- git clone https://github.com/toml-lang/toml.git
-- cmake -DCMAKE_CXX_COMPILER=$COMPILER -DCMAKE_CXX_STANDARD=$CXX_STANDARD ..
+- echo "COMPILER     = ${COMPILER}"
+- echo "CXX_STANDARD = ${CXX_STANDARD}"
+- cmake -DCMAKE_CXX_COMPILER=$COMPILER -DCMAKE_CXX_STANDARD=$CXX_STANDARD -DTOML11_REQUIRE_FILESYSTEM_LIBRARY=${REQUIRE_FILESYSTEM_LIBRARY} -Dtoml11_BUILD_TEST=ON -DTOML11_USE_UNRELEASED_TOML_FEATURES=${TOML_HEAD} -Dtoml11_TEST_WITH_ASAN=${WITH_ASAN} -Dtoml11_TEST_WITH_UBSAN=${WITH_UBSAN} ..
 - make
 - ctest --output-on-failure

CMakeLists.txt

@@ -1,24 +1,17 @@
-cmake_minimum_required(VERSION 2.8)
+cmake_minimum_required(VERSION 3.1)
 enable_testing()
 
-project(toml11)
+project(toml11 VERSION 3.6.1)
 
-set(toml11_VERSION_MAYOR  2)
-set(toml11_VERSION_MINOR  4)
-set(toml11_VERSION_PATCH  0)
-set(toml11_VERSION
-  "${toml11_VERSION_MAYOR}.${toml11_VERSION_MINOR}.${toml11_VERSION_PATCH}"
-)
-
-option(toml11_BUILD_TEST "Build toml tests" ON)
+option(toml11_BUILD_TEST "Build toml tests" OFF)
+option(toml11_TEST_WITH_ASAN  "use LLVM address sanitizer" OFF)
+option(toml11_TEST_WITH_UBSAN "use LLVM undefined behavior sanitizer" OFF)
 
 include(CheckCXXCompilerFlag)
 if("${CMAKE_VERSION}" VERSION_GREATER 3.1)
-    set(CMAKE_CXX_EXTENSIONS OFF)
-    if(NOT DEFINED CMAKE_CXX_STANDARD)
-        set(CMAKE_CXX_STANDARD 11)
-    endif()
-    set(CXX_STANDARD_REQUIRED ON)
+    set(CMAKE_CXX_STANDARD 11 CACHE STRING "The C++ standard whose features are requested to build all targets.")
+    set(CMAKE_CXX_STANDARD_REQUIRED ON CACHE BOOL "Boolean describing whether the value of CXX_STANDARD is a requirement.")
+    set(CMAKE_CXX_EXTENSIONS OFF CACHE BOOL "Boolean specifying whether compiler specific extensions are requested.")
 else()
     # Manually check for C++11 compiler flag.
     CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
@@ -44,6 +37,11 @@ else()
     endif()
 endif()
 
+if(MSVC)
+    add_definitions("/Zc:__cplusplus") # define __cplusplus value correctly
+    add_definitions("/utf-8")          # enable to use u8"" literal
+endif()
+
 # Set some common directories
 include(GNUInstallDirs)
 set(toml11_install_cmake_dir         ${CMAKE_INSTALL_LIBDIR}/cmake/toml11)

appveyor.yml

@@ -17,10 +17,9 @@ build_script:
   - cd C:\toml11
   - mkdir build
   - cd build
-  - git clone https://github.com/toml-lang/toml.git
-  - file --mime-encoding toml/tests/hard_example_unicode.toml
-  - cmake -G"%generator%" -DBOOST_ROOT=C:/Libraries/boost_1_63_0 ..
+  - cmake -G"%generator%" -DBOOST_ROOT=C:/Libraries/boost_1_69_0 -Dtoml11_BUILD_TEST=ON ..
   - cmake --build . --config "%configuration%"
+  - file --mime-encoding tests/toml/tests/hard_example_unicode.toml
 
 test_script:
   - ctest --build-config "%configuration%" --timeout 300 --output-on-failure

tests/CMakeLists.txt

@@ -1,5 +1,15 @@
+include(ExternalProject)
+ExternalProject_Add(toml
+        SOURCE_DIR ${CMAKE_CURRENT_BINARY_DIR}/toml
+        GIT_REPOSITORY https://github.com/toml-lang/toml
+        GIT_TAG v0.5.0
+        CONFIGURE_COMMAND ""
+        BUILD_COMMAND ""
+        INSTALL_COMMAND "")
+
 set(TEST_NAMES
     test_datetime
+    test_string
     test_utility
     test_result
     test_traits
@@ -23,8 +33,10 @@ set(TEST_NAMES
     test_literals
     test_comments
     test_get
-    test_get_related_func
-    test_from_toml
+    test_get_or
+    test_find
+    test_find_or
+    test_expect
     test_parse_file
     test_serialize_file
     test_parse_unicode
@@ -33,16 +45,68 @@ set(TEST_NAMES
     test_extended_conversions
 )
 
-CHECK_CXX_COMPILER_FLAG("-Wall" COMPILER_SUPPORTS_WALL)
+CHECK_CXX_COMPILER_FLAG("-Wall"      COMPILER_SUPPORTS_WALL)
+CHECK_CXX_COMPILER_FLAG("-Wextra"    COMPILER_SUPPORTS_WEXTRA)
 CHECK_CXX_COMPILER_FLAG("-Wpedantic" COMPILER_SUPPORTS_WPEDANTIC)
+CHECK_CXX_COMPILER_FLAG("-Werror"    COMPILER_SUPPORTS_WERROR)
+
+CHECK_CXX_COMPILER_FLAG("-Wsign-conversion"     COMPILER_SUPPORTS_WSIGN_CONVERSION)
+CHECK_CXX_COMPILER_FLAG("-Wconversion"          COMPILER_SUPPORTS_WCONVERSION)
+CHECK_CXX_COMPILER_FLAG("-Wduplicated-cond"     COMPILER_SUPPORTS_WDUPLICATED_COND)
+CHECK_CXX_COMPILER_FLAG("-Wduplicated-branches" COMPILER_SUPPORTS_WDUPLICATED_BRANCHES)
+CHECK_CXX_COMPILER_FLAG("-Wlogical-op"          COMPILER_SUPPORTS_WLOGICAL_OP)
+CHECK_CXX_COMPILER_FLAG("-Wuseless-cast"        COMPILER_SUPPORTS_WUSELESS_CAST)
+CHECK_CXX_COMPILER_FLAG("-Wdouble-promotion"    COMPILER_SUPPORTS_WDOUBLE_PROMOTION)
+CHECK_CXX_COMPILER_FLAG("-Wrange-loop-analysis" COMPILER_SUPPORTS_WRANGE_LOOP_ANALYSIS)
+CHECK_CXX_COMPILER_FLAG("-Wundef"               COMPILER_SUPPORTS_WUNDEF)
 
 if(COMPILER_SUPPORTS_WALL)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
 endif()
-
+if(COMPILER_SUPPORTS_WEXTRA)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wextra")
+endif()
 if(COMPILER_SUPPORTS_WPEDANTIC)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wpedantic")
 endif()
+if(COMPILER_SUPPORTS_WERROR)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror")
+endif()
+if(COMPILER_SUPPORTS_WSIGN_CONVERSION)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wsign-conversion")
+endif()
+if(COMPILER_SUPPORTS_WCONVERSION)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wconversion")
+endif()
+if(COMPILER_SUPPORTS_WDUPLICATED_COND)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wduplicated-cond")
+endif()
+if(COMPILER_SUPPORTS_WDUPLICATED_BRANCHES)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wduplicated-branches")
+endif()
+if(COMPILER_SUPPORTS_WLOGICAL_OP)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wlogical-op")
+endif()
+if(COMPILER_SUPPORTS_WUSELESS_CAST)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wuseless-cast")
+endif()
+if(COMPILER_SUPPORTS_WDOUBLE_PROMOTION)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wdouble-promotion")
+endif()
+if(COMPILER_SUPPORTS_WRANGE_LOOP_ANALYSIS)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wrange-loop-analysis")
+endif()
+if(COMPILER_SUPPORTS_WUNDEF)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wundef")
+endif()
+
+option(TOML11_USE_UNRELEASED_TOML_FEATURES
+    "use features in toml-lang/toml master while testing" OFF)
+
+if(TOML11_USE_UNRELEASED_TOML_FEATURES)
+    message(STATUS "adding TOML11_USE_UNRELEASED_TOML_FEATURES flag")
+    add_definitions("-DTOML11_USE_UNRELEASED_TOML_FEATURES")
+endif()
 
 # Disable some MSVC warnings
 if(MSVC)
@@ -86,11 +150,61 @@ find_package(Boost COMPONENTS unit_test_framework REQUIRED)
 add_definitions(-DBOOST_TEST_DYN_LINK)
 add_definitions(-DUNITTEST_FRAMEWORK_LIBRARY_EXIST)
 
+# check which standard library implementation is used. If libstdc++ is used,
+# it will fail to compile. It compiles if libc++ is used.
+include(CheckCXXSourceCompiles)
+check_cxx_source_compiles("
+#include <cstddef>
+#ifdef __GLIBCXX__
+    static_assert(false);
+#endif
+int main() {
+    return 0;
+}" TOML11_WITH_LIBCXX_LIBRARY)
+
+# LLVM 8 requires -lc++fs if compiled with libc++ to use <filesystem>.
+# LLVM 9+ does not require any special library.
+# GCC 8 requires -lstdc++fs. GCC 9+ does not require it.
+#
+# Yes, we can check the version of the compiler used in the current build
+# directly in CMake. But, in most cases, clang build uses libstdc++ as the
+# standard library implementation and it makes the condition complicated.
+# In many environment, the default installed C++ compiler is GCC and libstdc++
+# is installed along with it. In most build on such an environment, even if we
+# chose clang as the C++ compiler, still libstdc++ is used. Checking default
+# gcc version makes the condition complicated.
+# The purpose of this file is to compile tests. We know the environment on which
+# the tests run. We can set this option and, I think, it is easier and better.
+option(TOML11_REQUIRE_FILESYSTEM_LIBRARY "need to link -lstdc++fs or -lc++fs" OFF)
+
 foreach(TEST_NAME ${TEST_NAMES})
     add_executable(${TEST_NAME} ${TEST_NAME}.cpp)
     target_link_libraries(${TEST_NAME} ${Boost_UNIT_TEST_FRAMEWORK_LIBRARY} toml11::toml11)
+
+    # to compile tests with <filesystem>...
+    if(TOML11_REQUIRE_FILESYSTEM_LIBRARY)
+        if(TOML11_WITH_LIBCXX_LIBRARY)
+            target_link_libraries(${TEST_NAME} "c++fs")
+        else()
+            target_link_libraries(${TEST_NAME} "stdc++fs")
+        endif()
+    endif()
+
     target_include_directories(${TEST_NAME} PRIVATE ${Boost_INCLUDE_DIRS})
-    add_test(NAME ${TEST_NAME} COMMAND ${TEST_NAME} WORKING_DIRECTORY ${PROJECT_BINARY_DIR})
+
+    if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+        if(toml11_TEST_WITH_ASAN)
+            set_target_properties(${TEST_NAME} PROPERTIES
+                COMPILE_FLAGS "-fsanitize=address -fno-omit-frame-pointer"
+                LINK_FLAGS    "-fsanitize=address -fno-omit-frame-pointer")
+        elseif(toml11_TEST_WITH_UBSAN)
+            set_target_properties(${TEST_NAME} PROPERTIES
+                COMPILE_FLAGS "-fsanitize=undefined"
+                LINK_FLAGS    "-fsanitize=undefined")
+        endif()
+    endif()
+
+    add_test(NAME ${TEST_NAME} COMMAND ${TEST_NAME} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
 
     # Set the PATH to be able to find Boost DLL
     if(WIN32)
@@ -101,8 +215,15 @@ foreach(TEST_NAME ${TEST_NAMES})
     endif()
 endforeach(TEST_NAME)
 
+
 # this test is to check it compiles. it will not run
 add_executable(test_multiple_translation_unit
                test_multiple_translation_unit_1.cpp
                test_multiple_translation_unit_2.cpp)
 target_link_libraries(test_multiple_translation_unit toml11::toml11)
+
+if(WIN32)
+    add_executable(test_windows test_windows.cpp)
+    target_link_libraries(test_windows toml11::toml11)
+endif()
+

tests/check_serialization.cpp

@@ -0,0 +1,57 @@
+#include "toml.hpp"
+#include <iostream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    if(argc != 2)
+    {
+        std::cerr << "usage: ./check [filename]" << std::endl;
+        return 1;
+    }
+
+    const std::string filename(argv[1]);
+
+    {
+        const auto data = toml::parse(filename);
+        {
+            std::ofstream ofs("tmp.toml");
+            ofs << std::setprecision(16) << std::setw(80) << data;
+        }
+        const auto serialized = toml::parse("tmp.toml");
+
+        if(data != serialized)
+        {
+            std::cerr << "============================================================\n";
+            std::cerr << "result (w/o comment) different: " << filename << std::endl;
+            std::cerr << "------------------------------------------------------------\n";
+            std::cerr << "# serialized\n";
+            std::cerr << serialized;
+            std::cerr << "------------------------------------------------------------\n";
+            std::cerr << "# data\n";
+            std::cerr << data;
+            return 1;
+        }
+    }
+    {
+        const auto data = toml::parse<toml::preserve_comments>(filename);
+        {
+            std::ofstream ofs("tmp.toml");
+            ofs << std::setprecision(16) << std::setw(80) << data;
+        }
+        const auto serialized = toml::parse<toml::preserve_comments>("tmp.toml");
+        if(data != serialized)
+        {
+            std::cerr << "============================================================\n";
+            std::cerr << "result (w/  comment) different: " << filename << std::endl;
+            std::cerr << "------------------------------------------------------------\n";
+            std::cerr << "# serialized\n";
+            std::cerr << serialized;
+            std::cerr << "------------------------------------------------------------\n";
+            std::cerr << "# data\n";
+            std::cerr << data;
+            return 1;
+        }
+    }
+    return 0;
+}

tests/check_toml_test.cpp

@@ -84,9 +84,7 @@ struct json_serializer
         {
             if(!is_first) {std::cout << ", ";}
             is_first = false;
-            std::cout << toml::format(toml::string(elem.first),
-                                      std::numeric_limits<std::size_t>::max());
-            std::cout << ':';
+            std::cout << this->format_key(elem.first) << ':';
             toml::visit(*this, elem.second);
         }
         std::cout << '}';
@@ -112,6 +110,12 @@ struct json_serializer
         }
         return retval;
     }
+
+    std::string format_key(const std::string& s) const
+    {
+        const auto quote("\"");
+        return quote + escape_string(s) + quote;
+    }
 };
 
 int main()

tests/test_comments.cpp

@@ -10,116 +10,542 @@
 
 BOOST_AUTO_TEST_CASE(test_comment_before)
 {
-    using namespace toml::literals::toml_literals;
     {
-        const toml::value v = u8R"(
+        const std::string file = R"(
             # comment for a.
             a = 42
             # comment for b.
             b = "baz"
-        )"_toml;
+        )";
+        std::istringstream iss(file);
+        const auto v = toml::parse<toml::preserve_comments>(iss);
 
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment_before(), u8"# comment for a.");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment_before(), u8"# comment for b.");
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment_inline(), "");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment_inline(), "");
+        const auto& a = toml::find(v, "a");
+        const auto& b = toml::find(v, "b");
 
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment(), u8"# comment for a.");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment(), u8"# comment for b.");
+        BOOST_TEST(a.comments().size()  == 1u);
+        BOOST_TEST(a.comments().front() == " comment for a.");
+        BOOST_TEST(b.comments().size()  == 1u);
+        BOOST_TEST(b.comments().front() == " comment for b.");
     }
-
     {
-        const toml::value v = u8R"(
+        const std::string file = R"(
             # comment for a.
             # another comment for a.
             a = 42
             # comment for b.
             # also comment for b.
             b = "baz"
-        )"_toml;
+        )";
 
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment_before(), u8R"(# comment for a.
-# another comment for a.)");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment_before(), u8R"(# comment for b.
-# also comment for b.)");
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment_inline(), u8"");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment_inline(), u8"");
+        std::istringstream iss(file);
+        const auto v = toml::parse<toml::preserve_comments>(iss);
 
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment(), u8R"(# comment for a.
-# another comment for a.)");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment(), u8R"(# comment for b.
-# also comment for b.)");
+        const auto& a = toml::find(v, "a");
+        const auto& b = toml::find(v, "b");
+
+        BOOST_TEST(a.comments().size()  == 2u);
+        BOOST_TEST(a.comments().front() == " comment for a.");
+        BOOST_TEST(a.comments().back()  == " another comment for a.");
+        BOOST_TEST(b.comments().size()  == 2u);
+        BOOST_TEST(b.comments().front() == " comment for b.");
+        BOOST_TEST(b.comments().back()  == " also comment for b.");
     }
 }
 
 BOOST_AUTO_TEST_CASE(test_comment_inline)
 {
-    using namespace toml::literals::toml_literals;
     {
-        const toml::value v = u8R"(
+        const std::string file = R"(
             a = 42    # comment for a.
             b = "baz" # comment for b.
-        )"_toml;
+        )";
 
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment_before(), "");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment_before(), "");
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment_inline(), u8"# comment for a.");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment_inline(), u8"# comment for b.");
+        std::istringstream iss(file);
+        const auto v = toml::parse<toml::preserve_comments>(iss);
 
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment(), u8"# comment for a.");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment(), u8"# comment for b.");
+        const auto& a = toml::find(v, "a");
+        const auto& b = toml::find(v, "b");
+
+        BOOST_TEST(a.comments().size()  == 1u);
+        BOOST_TEST(a.comments().front() == " comment for a.");
+        BOOST_TEST(b.comments().size()  == 1u);
+        BOOST_TEST(b.comments().front() == " comment for b.");
     }
     {
-        const toml::value v = u8R"(
-            a = [    # comment for a.
+        const std::string file = R"(
+            a = [
                 42,
-            ] # this also.
-            b = [ # comment for b.
-                "bar",
-            ]
-            c = [
-                3.14, # this is not a comment for c, but 3.14.
-            ] # comment for c.
-        )"_toml;
+            ] # comment for a.
+            b = [
+                "bar", # this is not a comment for b, but "bar"
+            ] # this is a comment for b.
+        )";
 
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment_before(), "");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment_before(), "");
-        BOOST_CHECK_EQUAL(toml::find(v, "c").comment_before(), "");
+        std::istringstream iss(file);
+        const auto v = toml::parse<toml::preserve_comments>(iss);
 
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment_inline(), u8R"(# comment for a.
-# this also.)");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment_inline(), u8"# comment for b.");
-        BOOST_CHECK_EQUAL(toml::find(v, "c").comment_inline(), u8"# comment for c.");
+        const auto& a  = toml::find(v, "a");
+        const auto& b  = toml::find(v, "b");
+        const auto& b0 = b.as_array().at(0);
 
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment(),  u8R"(# comment for a.
-# this also.)");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment(), u8"# comment for b.");
-        BOOST_CHECK_EQUAL(toml::find(v, "c").comment(), u8"# comment for c.");
-
-        const auto& c0 = toml::find<toml::array>(v, "c").at(0);
-        BOOST_CHECK_EQUAL(c0.comment(), u8"# this is not a comment for c, but 3.14.");
+        BOOST_TEST(a.comments().size()   == 1u);
+        BOOST_TEST(a.comments().front()  == " comment for a.");
+        BOOST_TEST(b.comments().size()   == 1u);
+        BOOST_TEST(b.comments().front()  == " this is a comment for b.");
+        BOOST_TEST(b0.comments().size()  == 1u);
+        BOOST_TEST(b0.comments().front() == " this is not a comment for b, but \"bar\"");
     }
 }
 
 BOOST_AUTO_TEST_CASE(test_comment_both)
 {
-    using namespace toml::literals::toml_literals;
     {
-        const toml::value v = u8R"(
+        const std::string file = R"(
             # comment for a.
             a = 42 # inline comment for a.
             # comment for b.
             b = "baz" # inline comment for b.
-        )"_toml;
+            # comment for c.
+            c = [ # this comment will be ignored
+                # comment for the first element.
+                10 # this also.
+            ] # another comment for c.
+        )";
 
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment_before(), "# comment for a.");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment_before(), "# comment for b.");
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment_inline(), "# inline comment for a.");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment_inline(), "# inline comment for b.");
+        std::istringstream iss(file);
+        const auto v = toml::parse<toml::preserve_comments>(iss);
 
-        BOOST_CHECK_EQUAL(toml::find(v, "a").comment(), u8R"(# comment for a.
-# inline comment for a.)");
-        BOOST_CHECK_EQUAL(toml::find(v, "b").comment(), u8R"(# comment for b.
-# inline comment for b.)");
+        const auto& a  = toml::find(v, "a");
+        const auto& b  = toml::find(v, "b");
+        const auto& c  = toml::find(v, "c");
+        const auto& c0 = c.as_array().at(0);
+
+        BOOST_TEST(a.comments().size()  == 2u);
+        BOOST_TEST(a.comments().front() == " comment for a.");
+        BOOST_TEST(a.comments().back()  == " inline comment for a.");
+        BOOST_TEST(b.comments().size()  == 2u);
+        BOOST_TEST(b.comments().front() == " comment for b.");
+        BOOST_TEST(b.comments().back()  == " inline comment for b.");
+
+        BOOST_TEST(c.comments().size()  == 2u);
+        BOOST_TEST(c.comments().front() == " comment for c.");
+        BOOST_TEST(c.comments().back()  == " another comment for c.");
+
+        BOOST_TEST(c0.comments().size()  == 2u);
+        BOOST_TEST(c0.comments().front() == " comment for the first element.");
+        BOOST_TEST(c0.comments().back()  == " this also.");
     }
 }
+
+BOOST_AUTO_TEST_CASE(test_comments_on_implicit_values)
+{
+    {
+        const std::string file = R"(
+            # comment for the first element of array-of-tables.
+            [[array-of-tables]]
+            foo = "bar"
+        )";
+        std::istringstream iss(file);
+        const auto v = toml::parse<toml::preserve_comments>(iss);
+
+        const auto aot = toml::find(v, "array-of-tables");
+        const auto elm = aot.at(0);
+        BOOST_TEST(aot.comments().empty());
+        BOOST_TEST(elm.comments().size() == 1);
+        BOOST_TEST(elm.comments().front() == " comment for the first element of array-of-tables.");
+    }
+    {
+        const std::string file = R"(
+            # comment for the array itself
+            array-of-tables = [
+                # comment for the first element of array-of-tables.
+                {foo = "bar"}
+            ]
+        )";
+        std::istringstream iss(file);
+        const auto v = toml::parse<toml::preserve_comments>(iss);
+
+        const auto aot = toml::find(v, "array-of-tables");
+        const auto elm = aot.at(0);
+        BOOST_TEST(aot.comments().size() == 1);
+        BOOST_TEST(aot.comments().front() == " comment for the array itself");
+        BOOST_TEST(elm.comments().size() == 1);
+        BOOST_TEST(elm.comments().front() == " comment for the first element of array-of-tables.");
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_discard_comment)
+{
+    const std::string file = R"(
+        # comment for a.
+        a = 42 # inline comment for a.
+        # comment for b.
+        b = "baz" # inline comment for b.
+        # comment for c.
+        c = [ # this comment will be ignored
+            # comment for the first element.
+            10 # this also.
+        ] # another comment for c.
+    )";
+
+    std::istringstream iss(file);
+    const auto v = toml::parse(iss);
+
+    const auto& a  = toml::find(v, "a");
+    const auto& b  = toml::find(v, "b");
+    const auto& c  = toml::find(v, "c");
+    const auto& c0 = c.as_array().at(0);
+
+    BOOST_TEST(a.comments().empty());
+    BOOST_TEST(b.comments().empty());
+    BOOST_TEST(c.comments().empty());
+    BOOST_TEST(c0.comments().empty());
+}
+
+BOOST_AUTO_TEST_CASE(test_construct_value_with_comments)
+{
+    using value_type = toml::basic_value<toml::preserve_comments>;
+    {
+        const value_type v(true, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_boolean());
+        BOOST_TEST(v.as_boolean() == true);
+    }
+    {
+        const value_type v(42, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_integer());
+        BOOST_TEST(v.as_integer() == 42);
+    }
+    {
+        const value_type v(3.14, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_floating());
+        BOOST_TEST(v.as_floating() == 3.14);
+    }
+    {
+        const value_type v(toml::string("str"), {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_string());
+        BOOST_TEST(v.as_string() == "str");
+    }
+    {
+        const value_type v(std::string("str"), {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_string());
+        BOOST_TEST(v.as_string() == "str");
+    }
+    {
+        const value_type v(std::string("str"), toml::string_t::literal,
+                           {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_string());
+        BOOST_TEST(v.as_string() == "str");
+    }
+    {
+        const value_type v("str", {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_string());
+        BOOST_TEST(v.as_string() == "str");
+    }
+    {
+        const value_type v("str", toml::string_t::literal,
+                           {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_string());
+        BOOST_TEST(v.as_string() == "str");
+    }
+#if __cplusplus >= 201703L
+    {
+        using namespace std::literals::string_view_literals;
+        const value_type v("str"sv, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_string());
+        BOOST_TEST(v.as_string() == "str");
+    }
+    {
+        using namespace std::literals::string_view_literals;
+        const value_type v("str"sv, toml::string_t::literal,
+                           {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_string());
+        BOOST_TEST(v.as_string() == "str");
+    }
+#endif
+    const toml::local_date      ld{2019, toml::month_t::Apr, 1};
+    const toml::local_time      lt{12, 30, 45};
+    const toml::local_datetime  ldt{ld, lt};
+    const toml::offset_datetime odt{ld, lt, toml::time_offset{9, 0}};
+    {
+        const value_type v(ld, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_local_date());
+        BOOST_TEST(v.as_local_date() == ld);
+    }
+    {
+        const value_type v(lt, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_local_time());
+        BOOST_TEST(v.as_local_time() == lt);
+    }
+    {
+        const toml::local_time three_hours{3,0,0};
+        const value_type v(std::chrono::hours(3), {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_local_time());
+        BOOST_TEST(v.as_local_time() == three_hours);
+    }
+    {
+        const value_type v(ldt, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_local_datetime());
+        BOOST_TEST(v.as_local_datetime() == ldt);
+    }
+    {
+        const value_type v(odt, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_offset_datetime());
+        BOOST_TEST(v.as_offset_datetime() == odt);
+    }
+    {
+        const auto systp = static_cast<std::chrono::system_clock::time_point>(odt);
+        const value_type v(systp, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_offset_datetime());
+
+        // While the conversion, the information about time offset may change.
+        const auto systp2 = static_cast<std::chrono::system_clock::time_point>(
+                v.as_offset_datetime());
+        const bool result = systp == systp2; // because there is no operator<<
+        BOOST_TEST(result);
+    }
+    {
+        const typename value_type::array_type a{1,2,3,4,5};
+        const value_type v(a, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_array());
+        BOOST_TEST(v.as_array().at(0).is_integer());
+        BOOST_TEST(v.as_array().at(1).is_integer());
+        BOOST_TEST(v.as_array().at(2).is_integer());
+        BOOST_TEST(v.as_array().at(3).is_integer());
+        BOOST_TEST(v.as_array().at(4).is_integer());
+        BOOST_TEST(v.as_array().at(0).as_integer() == 1);
+        BOOST_TEST(v.as_array().at(1).as_integer() == 2);
+        BOOST_TEST(v.as_array().at(2).as_integer() == 3);
+        BOOST_TEST(v.as_array().at(3).as_integer() == 4);
+        BOOST_TEST(v.as_array().at(4).as_integer() == 5);
+    }
+    {
+        const std::initializer_list<int> a = {1,2,3,4,5};
+        const value_type v(a, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_array());
+        BOOST_TEST(v.as_array().at(0).is_integer());
+        BOOST_TEST(v.as_array().at(1).is_integer());
+        BOOST_TEST(v.as_array().at(2).is_integer());
+        BOOST_TEST(v.as_array().at(3).is_integer());
+        BOOST_TEST(v.as_array().at(4).is_integer());
+        BOOST_TEST(v.as_array().at(0).as_integer() == 1);
+        BOOST_TEST(v.as_array().at(1).as_integer() == 2);
+        BOOST_TEST(v.as_array().at(2).as_integer() == 3);
+        BOOST_TEST(v.as_array().at(3).as_integer() == 4);
+        BOOST_TEST(v.as_array().at(4).as_integer() == 5);
+    }
+    {
+        const std::vector<int> a = {1,2,3,4,5};
+        const value_type v(a, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_array());
+        BOOST_TEST(v.as_array().at(0).is_integer());
+        BOOST_TEST(v.as_array().at(1).is_integer());
+        BOOST_TEST(v.as_array().at(2).is_integer());
+        BOOST_TEST(v.as_array().at(3).is_integer());
+        BOOST_TEST(v.as_array().at(4).is_integer());
+        BOOST_TEST(v.as_array().at(0).as_integer() == 1);
+        BOOST_TEST(v.as_array().at(1).as_integer() == 2);
+        BOOST_TEST(v.as_array().at(2).as_integer() == 3);
+        BOOST_TEST(v.as_array().at(3).as_integer() == 4);
+        BOOST_TEST(v.as_array().at(4).as_integer() == 5);
+    }
+    {
+        const typename value_type::table_type t{
+                {"key1", 42}, {"key2", "foobar"}
+            };
+        const value_type v(t, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_table());
+        BOOST_TEST(v.as_table().at("key1").is_integer());
+        BOOST_TEST(v.as_table().at("key1").as_integer() == 42);
+        BOOST_TEST(v.as_table().at("key2").is_string());
+        BOOST_TEST(v.as_table().at("key2").as_string() == "foobar");
+    }
+    {
+        const std::initializer_list<std::pair<std::string, value_type>> t{
+                {"key1", 42}, {"key2", "foobar"}
+            };
+        const value_type v(t, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_table());
+        BOOST_TEST(v.as_table().at("key1").is_integer());
+        BOOST_TEST(v.as_table().at("key1").as_integer() == 42);
+        BOOST_TEST(v.as_table().at("key2").is_string());
+        BOOST_TEST(v.as_table().at("key2").as_string() == "foobar");
+    }
+    {
+        const std::map<std::string, value_type> t{
+                {"key1", 42}, {"key2", "foobar"}
+            };
+        const value_type v(t, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_table());
+        BOOST_TEST(v.as_table().at("key1").is_integer());
+        BOOST_TEST(v.as_table().at("key1").as_integer() == 42);
+        BOOST_TEST(v.as_table().at("key2").is_string());
+        BOOST_TEST(v.as_table().at("key2").as_string() == "foobar");
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_overwrite_comments)
+{
+    using value_type = toml::basic_value<toml::preserve_comments>;
+    {
+        const value_type v(42, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_integer());
+        BOOST_TEST(v.as_integer() == 42);
+
+        const value_type u(v, {"comment3", "comment4"});
+        BOOST_TEST(u.comments().size() == 2u);
+        BOOST_TEST(u.comments().at(0)  == "comment3");
+        BOOST_TEST(u.comments().at(1)  == "comment4");
+        BOOST_TEST(u.is_integer());
+        BOOST_TEST(u.as_integer() == 42);
+    }
+    {
+        const value_type v(42, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_integer());
+        BOOST_TEST(v.as_integer() == 42);
+
+        const value_type u(v);
+        BOOST_TEST(u.comments().size() == 2u);
+        BOOST_TEST(u.comments().at(0)  == "comment1");
+        BOOST_TEST(u.comments().at(1)  == "comment2");
+        BOOST_TEST(u.is_integer());
+        BOOST_TEST(u.as_integer() == 42);
+    }
+    {
+        const value_type v(42, {"comment1", "comment2"});
+        BOOST_TEST(v.comments().size() == 2u);
+        BOOST_TEST(v.comments().at(0)  == "comment1");
+        BOOST_TEST(v.comments().at(1)  == "comment2");
+        BOOST_TEST(v.is_integer());
+        BOOST_TEST(v.as_integer() == 42);
+
+        const value_type u(v, {});
+        BOOST_TEST(u.comments().size() == 0u);
+        BOOST_TEST(u.is_integer());
+        BOOST_TEST(u.as_integer() == 42);
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_output_comments)
+{
+    using value_type = toml::basic_value<toml::preserve_comments>;
+    {
+        const value_type v(42, {"comment1", "comment2"});
+        std::ostringstream oss;
+        oss << v.comments();
+
+        std::ostringstream ref;
+        ref << "#comment1\n";
+        ref << "#comment2\n";
+
+        BOOST_TEST(oss.str() == ref.str());
+    }
+    {
+        const value_type v(42, {"comment1", "comment2"});
+        std::ostringstream oss;
+
+        // If v is not a table, toml11 assumes that user is writing something
+        // like the following.
+
+        oss << "answer = " << v;
+
+        BOOST_TEST(oss.str() == "answer = 42 #comment1comment2");
+    }
+
+    {
+        const value_type v(42, {"comment1", "comment2"});
+        std::ostringstream oss;
+
+        // If v is not a table, toml11 assumes that user is writing something
+        // like the following.
+
+        oss << toml::nocomment << "answer = " << v;
+
+        BOOST_TEST(oss.str() == "answer = 42");
+    }
+
+    {
+        const value_type v(42, {"comment1", "comment2"});
+        std::ostringstream oss;
+
+        // If v is not a table, toml11 assumes that user is writing something
+        // like the following.
+
+        oss << toml::nocomment << toml::showcomment << "answer = " << v;
+
+        BOOST_TEST(oss.str() == "answer = 42 #comment1comment2");
+    }
+
+}

tests/test_datetime.cpp

@@ -11,47 +11,47 @@ BOOST_AUTO_TEST_CASE(test_local_date)
 {
     const toml::local_date date(2018, toml::month_t::Jan, 1);
     const toml::local_date date1(date);
-    BOOST_CHECK_EQUAL(date, date1);
+    BOOST_TEST(date == date1);
 
     const std::chrono::system_clock::time_point tp(date);
     const toml::local_date date2(tp);
-    BOOST_CHECK_EQUAL(date, date2);
+    BOOST_TEST(date == date2);
 
     const toml::local_date date3(2017, toml::month_t::Dec, 31);
-    BOOST_CHECK(date > date3);
+    BOOST_TEST(date > date3);
 
     std::ostringstream oss;
     oss << date;
-    BOOST_CHECK_EQUAL(oss.str(), std::string("2018-01-01"));
+    BOOST_TEST(oss.str() == std::string("2018-01-01"));
 }
 
 BOOST_AUTO_TEST_CASE(test_local_time)
 {
     const toml::local_time time(12, 30, 45);
     const toml::local_time time1(time);
-    BOOST_CHECK_EQUAL(time, time1);
+    BOOST_TEST(time == time1);
 
     const std::chrono::nanoseconds dur(time);
     std::chrono::nanoseconds ns(0);
     ns += std::chrono::hours  (12);
     ns += std::chrono::minutes(30);
     ns += std::chrono::seconds(45);
-    BOOST_CHECK_EQUAL(dur.count(), ns.count());
+    BOOST_TEST(dur.count() == ns.count());
 
     const toml::local_time time3(12, 15, 45);
-    BOOST_CHECK(time > time3);
+    BOOST_TEST(time > time3);
 
     {
         std::ostringstream oss;
         oss << time;
-        BOOST_CHECK_EQUAL(oss.str(), std::string("12:30:45"));
+        BOOST_TEST(oss.str() == std::string("12:30:45"));
     }
 
     {
         const toml::local_time time4(12, 30, 45, 123, 456);
         std::ostringstream oss;
         oss << time4;
-        BOOST_CHECK_EQUAL(oss.str(), std::string("12:30:45.123456"));
+        BOOST_TEST(oss.str() == std::string("12:30:45.123456"));
     }
 }
 
@@ -59,20 +59,20 @@ BOOST_AUTO_TEST_CASE(test_time_offset)
 {
     const toml::time_offset time(9, 30);
     const toml::time_offset time1(time);
-    BOOST_CHECK_EQUAL(time, time1);
+    BOOST_TEST(time == time1);
 
     const std::chrono::minutes dur(time);
     std::chrono::minutes m(0);
     m += std::chrono::hours  (9);
     m += std::chrono::minutes(30);
-    BOOST_CHECK_EQUAL(dur.count(), m.count());
+    BOOST_TEST(dur.count() == m.count());
 
     const toml::time_offset time2(9, 0);
-    BOOST_CHECK(time2 < time);
+    BOOST_TEST(time2 < time);
 
     std::ostringstream oss;
     oss << time;
-    BOOST_CHECK_EQUAL(oss.str(), std::string("+09:30"));
+    BOOST_TEST(oss.str() == std::string("+09:30"));
 }
 
 BOOST_AUTO_TEST_CASE(test_local_datetime)
@@ -80,15 +80,15 @@ BOOST_AUTO_TEST_CASE(test_local_datetime)
     const toml::local_datetime dt(toml::local_date(2018, toml::month_t::Jan, 1),
                                   toml::local_time(12, 30, 45));
     const toml::local_datetime dt1(dt);
-    BOOST_CHECK_EQUAL(dt, dt1);
+    BOOST_TEST(dt == dt1);
 
     const std::chrono::system_clock::time_point tp(dt);
     const toml::local_datetime dt2(tp);
-    BOOST_CHECK_EQUAL(dt, dt2);
+    BOOST_TEST(dt == dt2);
 
     std::ostringstream oss;
     oss << dt;
-    BOOST_CHECK_EQUAL(oss.str(), std::string("2018-01-01T12:30:45"));
+    BOOST_TEST(oss.str() == std::string("2018-01-01T12:30:45"));
 }
 
 BOOST_AUTO_TEST_CASE(test_offset_datetime)
@@ -97,17 +97,18 @@ BOOST_AUTO_TEST_CASE(test_offset_datetime)
                                    toml::local_time(12, 30, 45),
                                    toml::time_offset(9, 30));
     const toml::offset_datetime dt1(dt);
-    BOOST_CHECK_EQUAL(dt, dt1);
+    BOOST_TEST(dt == dt1);
 
     const std::chrono::system_clock::time_point tp1(dt);
     const toml::offset_datetime dt2(tp1);
     const std::chrono::system_clock::time_point tp2(dt2);
-    BOOST_CHECK(tp1 == tp2);
+    const bool tp_same = (tp1 == tp2);
+    BOOST_TEST(tp_same);
 
     {
         std::ostringstream oss;
         oss << dt;
-        BOOST_CHECK_EQUAL(oss.str(), std::string("2018-01-01T12:30:45+09:30"));
+        BOOST_TEST(oss.str() == std::string("2018-01-01T12:30:45+09:30"));
     }
     {
         const toml::offset_datetime dt3(
@@ -116,6 +117,6 @@ BOOST_AUTO_TEST_CASE(test_offset_datetime)
                 toml::time_offset(0, 0));
         std::ostringstream oss;
         oss << dt3;
-        BOOST_CHECK_EQUAL(oss.str(), std::string("2018-01-01T12:30:45Z"));
+        BOOST_TEST(oss.str() == std::string("2018-01-01T12:30:45Z"));
     }
 }

tests/test_error_detection.cpp

@@ -12,50 +12,19 @@
 BOOST_AUTO_TEST_CASE(test_detect_empty_key)
 {
     std::istringstream stream(std::string("= \"value\""));
-    bool exception_thrown = false;
-    try
-    {
-        toml::parse(stream, "test_detect_empty_key");
-    }
-    catch(const toml::syntax_error& syn)
-    {
-        // to see the error message
-        std::cerr << syn.what() << std::endl;
-        exception_thrown = true;
-    }
-    BOOST_CHECK(exception_thrown);
+    BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
 }
 
 BOOST_AUTO_TEST_CASE(test_detect_missing_value)
 {
     std::istringstream stream(std::string("a ="));
-    bool exception_thrown = false;
-    try
-    {
-        toml::parse(stream, "test_detect_missing_value");
-    }
-    catch(const toml::syntax_error& syn)
-    {
-        std::cerr << syn.what() << std::endl;
-        exception_thrown = true;
-    }
-    BOOST_CHECK(exception_thrown);
+    BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
 }
 
 BOOST_AUTO_TEST_CASE(test_detect_too_many_value)
 {
     std::istringstream stream(std::string("a = 1 = \"value\""));
-    bool exception_thrown = false;
-    try
-    {
-        toml::parse(stream, "test_detect_too_many_value");
-    }
-    catch(const toml::syntax_error& syn)
-    {
-        std::cerr << syn.what() << std::endl;
-        exception_thrown = true;
-    }
-    BOOST_CHECK(exception_thrown);
+    BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
 }
 
 BOOST_AUTO_TEST_CASE(test_detect_duplicate_table)
@@ -66,17 +35,7 @@ BOOST_AUTO_TEST_CASE(test_detect_duplicate_table)
             "[table]\n"
             "b = 42\n"
             ));
-    bool exception_thrown = false;
-    try
-    {
-        toml::parse(stream, "test_detect_duplicate_table");
-    }
-    catch(const toml::syntax_error& syn)
-    {
-        std::cerr << syn.what() << std::endl;
-        exception_thrown = true;
-    }
-    BOOST_CHECK(exception_thrown);
+    BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
 }
 
 BOOST_AUTO_TEST_CASE(test_detect_conflict_array_table)
@@ -87,17 +46,7 @@ BOOST_AUTO_TEST_CASE(test_detect_conflict_array_table)
             "[table]\n"
             "b = 42\n"
             ));
-    bool exception_thrown = false;
-    try
-    {
-        toml::parse(stream, "test_detect_conflict_array_table");
-    }
-    catch(const toml::syntax_error& syn)
-    {
-        std::cerr << syn.what() << std::endl;
-        exception_thrown = true;
-    }
-    BOOST_CHECK(exception_thrown);
+    BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
 }
 
 BOOST_AUTO_TEST_CASE(test_detect_conflict_table_array)
@@ -108,17 +57,7 @@ BOOST_AUTO_TEST_CASE(test_detect_conflict_table_array)
             "[[table]]\n"
             "b = 42\n"
             ));
-    bool exception_thrown = false;
-    try
-    {
-        toml::parse(stream, "test_detect_conflict_table_array");
-    }
-    catch(const toml::syntax_error& syn)
-    {
-        std::cerr << syn.what() << std::endl;
-        exception_thrown = true;
-    }
-    BOOST_CHECK(exception_thrown);
+    BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
 }
 
 BOOST_AUTO_TEST_CASE(test_detect_duplicate_value)
@@ -127,17 +66,7 @@ BOOST_AUTO_TEST_CASE(test_detect_duplicate_value)
             "a = 1\n"
             "a = 2\n"
             ));
-    bool exception_thrown = false;
-    try
-    {
-        toml::parse(stream, "test_detect_duplicate_value");
-    }
-    catch(const toml::syntax_error& syn)
-    {
-        std::cerr << syn.what() << std::endl;
-        exception_thrown = true;
-    }
-    BOOST_CHECK(exception_thrown);
+    BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
 }
 
 BOOST_AUTO_TEST_CASE(test_detect_conflicting_value)
@@ -146,35 +75,19 @@ BOOST_AUTO_TEST_CASE(test_detect_conflicting_value)
             "a.b   = 1\n"
             "a.b.c = 2\n"
             ));
-    bool exception_thrown = false;
-    try
-    {
-        toml::parse(stream, "test_detect_conflicting_value");
-    }
-    catch(const toml::syntax_error& syn)
-    {
-        std::cerr << syn.what() << std::endl;
-        exception_thrown = true;
-    }
-    BOOST_CHECK(exception_thrown);
+    BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
 }
 
 BOOST_AUTO_TEST_CASE(test_detect_inhomogeneous_array)
 {
+#ifdef TOML11_DISALLOW_HETEROGENEOUS_ARRAYS
     std::istringstream stream(std::string(
             "a = [1, 1.0]\n"
             ));
-    bool exception_thrown = false;
-    try
-    {
-        toml::parse(stream, "test_detect_inhomogeneous_array");
-    }
-    catch(const toml::syntax_error& syn)
-    {
-        std::cerr << syn.what() << std::endl;
-        exception_thrown = true;
-    }
-    BOOST_CHECK(exception_thrown);
+    BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
+#else
+    BOOST_TEST_MESSAGE("After v1.0.0-rc.1, heterogeneous arrays are allowed");
+#endif
 }
 
 BOOST_AUTO_TEST_CASE(test_detect_appending_array_of_table)
@@ -184,16 +97,5 @@ BOOST_AUTO_TEST_CASE(test_detect_appending_array_of_table)
             "[[a]]\n"
             "b = 2\n"
             ));
-    bool exception_thrown = false;
-    try
-    {
-        toml::parse(stream, "test_detect_appending_array_of_table");
-    }
-    catch(const toml::syntax_error& syn)
-    {
-        std::cerr << syn.what() << std::endl;
-        exception_thrown = true;
-    }
-    BOOST_CHECK(exception_thrown);
+    BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
 }
-

tests/test_expect.cpp

@@ -0,0 +1,30 @@
+#define BOOST_TEST_MODULE "test_expect"
+#ifdef UNITTEST_FRAMEWORK_LIBRARY_EXIST
+#include <boost/test/unit_test.hpp>
+#else
+#define BOOST_TEST_NO_LIB
+#include <boost/test/included/unit_test.hpp>
+#endif
+#include <toml.hpp>
+#include <map>
+#include <unordered_map>
+#include <list>
+#include <deque>
+#include <array>
+
+BOOST_AUTO_TEST_CASE(test_expect)
+{
+    {
+        toml::value v1(42);
+        toml::value v2(3.14);
+        const auto v1_or_0 = toml::expect<int>(v1).unwrap_or(0);
+        const auto v2_or_0 = toml::expect<int>(v2).unwrap_or(0);
+        BOOST_TEST(42 == v1_or_0);
+        BOOST_TEST( 0 == v2_or_0);
+
+        const auto v1_or_none = toml::expect<int>(v1).map([](int i){return std::to_string(i);}).unwrap_or(std::string("none"));
+        const auto v2_or_none = toml::expect<int>(v2).map([](int i){return std::to_string(i);}).unwrap_or(std::string("none"));
+        BOOST_TEST("42" ==   v1_or_none);
+        BOOST_TEST("none" == v2_or_none);
+    }
+}

tests/test_extended_conversions.cpp

@@ -6,6 +6,8 @@
 #include <boost/test/included/unit_test.hpp>
 #endif
 #include <toml.hpp>
+#include <deque>
+#include <map>
 
 namespace extlib
 {
@@ -31,6 +33,27 @@ struct bar
         return toml::table{{"a", this->a}, {"b", this->b}};
     }
 };
+
+struct baz
+{
+    int a;
+    std::string b;
+};
+struct qux
+{
+    int a;
+    std::string b;
+};
+
+struct foobar
+{
+    // via constructor
+    explicit foobar(const toml::value& v)
+        : a(toml::find<int>(v, "a")), b(toml::find<std::string>(v, "b"))
+    {}
+    int a;
+    std::string b;
+};
 } // extlib
 
 namespace toml
@@ -47,70 +70,478 @@ struct from<extlib::foo>
 template<>
 struct into<extlib::foo>
 {
-    static toml::table into_toml(const extlib::foo& f)
+    static toml::value into_toml(const extlib::foo& f)
+    {
+        return toml::value{{"a", f.a}, {"b", f.b}};
+    }
+};
+
+template<>
+struct from<extlib::baz>
+{
+    static extlib::baz from_toml(const toml::value& v)
+    {
+        return extlib::baz{toml::find<int>(v, "a"), toml::find<std::string>(v, "b")};
+    }
+};
+
+template<>
+struct into<extlib::qux>
+{
+    static toml::table into_toml(const extlib::qux& f)
     {
         return toml::table{{"a", f.a}, {"b", f.b}};
     }
 };
 } // toml
 
+// ---------------------------------------------------------------------------
+
+namespace extlib2
+{
+struct foo
+{
+    int a;
+    std::string b;
+};
+struct bar
+{
+    int a;
+    std::string b;
+
+    template<typename C, template<typename ...> class M, template<typename ...> class A>
+    void from_toml(const toml::basic_value<C, M, A>& v)
+    {
+        this->a = toml::find<int>(v, "a");
+        this->b = toml::find<std::string>(v, "b");
+        return ;
+    }
+
+    toml::table into_toml() const
+    {
+        return toml::table{{"a", this->a}, {"b", this->b}};
+    }
+};
+struct baz
+{
+    int a;
+    std::string b;
+};
+struct qux
+{
+    int a;
+    std::string b;
+};
+
+struct foobar
+{
+    template<typename C, template<typename ...> class M, template<typename ...> class A>
+    explicit foobar(const toml::basic_value<C, M, A>& v)
+        : a(toml::find<int>(v, "a")), b(toml::find<std::string>(v, "b"))
+    {}
+    int a;
+    std::string b;
+};
+
+} // extlib2
+
+namespace toml
+{
+template<>
+struct from<extlib2::foo>
+{
+    template<typename C, template<typename ...> class M, template<typename ...> class A>
+    static extlib2::foo from_toml(const toml::basic_value<C, M, A>& v)
+    {
+        return extlib2::foo{toml::find<int>(v, "a"), toml::find<std::string>(v, "b")};
+    }
+};
+
+template<>
+struct into<extlib2::foo>
+{
+    static toml::table into_toml(const extlib2::foo& f)
+    {
+        return toml::table{{"a", f.a}, {"b", f.b}};
+    }
+};
+
+template<>
+struct from<extlib2::baz>
+{
+    template<typename C, template<typename ...> class M, template<typename ...> class A>
+    static extlib2::baz from_toml(const toml::basic_value<C, M, A>& v)
+    {
+        return extlib2::baz{toml::find<int>(v, "a"), toml::find<std::string>(v, "b")};
+    }
+};
+
+template<>
+struct into<extlib2::qux>
+{
+    static toml::basic_value<toml::preserve_comments, std::map>
+    into_toml(const extlib2::qux& f)
+    {
+        return toml::basic_value<toml::preserve_comments, std::map>{
+            {"a", f.a}, {"b", f.b}
+        };
+    }
+};
+} // toml
+
+// ---------------------------------------------------------------------------
 
 BOOST_AUTO_TEST_CASE(test_conversion_by_member_methods)
 {
-    const toml::value v{{"a", 42}, {"b", "baz"}};
+    {
+        const toml::value v{{"a", 42}, {"b", "baz"}};
 
-    const auto foo = toml::get<extlib::foo>(v);
-    BOOST_CHECK_EQUAL(foo.a, 42);
-    BOOST_CHECK_EQUAL(foo.b, "baz");
+        const auto foo = toml::get<extlib::foo>(v);
+        BOOST_TEST(foo.a == 42);
+        BOOST_TEST(foo.b == "baz");
 
-    const toml::value v2(foo);
+        const toml::value v2(foo);
 
-    BOOST_CHECK_EQUAL(v, v2);
+        BOOST_TEST(v == v2);
+    }
+
+    {
+        const toml::value v{{"a", 42}, {"b", "baz"}};
+
+        const auto foo = toml::get<extlib2::foo>(v);
+        BOOST_TEST(foo.a == 42);
+        BOOST_TEST(foo.b == "baz");
+
+        const toml::value v2(foo);
+        BOOST_TEST(v == v2);
+    }
+
+    {
+        const toml::basic_value<toml::discard_comments, std::map, std::deque>
+            v{{"a", 42}, {"b", "baz"}};
+
+        const auto foo = toml::get<extlib2::foo>(v);
+        BOOST_TEST(foo.a == 42);
+        BOOST_TEST(foo.b == "baz");
+
+        const toml::basic_value<toml::discard_comments, std::map, std::deque>
+            v2(foo);
+
+        BOOST_TEST(v == v2);
+    }
 }
 
 BOOST_AUTO_TEST_CASE(test_conversion_by_specialization)
 {
-    const toml::value v{{"a", 42}, {"b", "baz"}};
+    {
+        const toml::value v{{"a", 42}, {"b", "baz"}};
 
-    const auto bar = toml::get<extlib::bar>(v);
-    BOOST_CHECK_EQUAL(bar.a, 42);
-    BOOST_CHECK_EQUAL(bar.b, "baz");
+        const auto bar = toml::get<extlib::bar>(v);
+        BOOST_TEST(bar.a == 42);
+        BOOST_TEST(bar.b == "baz");
 
-    const toml::value v2(bar);
+        const toml::value v2(bar);
 
-    BOOST_CHECK_EQUAL(v, v2);
+        BOOST_TEST(v == v2);
+    }
+    {
+        const toml::value v{{"a", 42}, {"b", "baz"}};
+
+        const auto bar = toml::get<extlib2::bar>(v);
+        BOOST_TEST(bar.a == 42);
+        BOOST_TEST(bar.b == "baz");
+
+        const toml::value v2(bar);
+
+        BOOST_TEST(v == v2);
+    }
+    {
+        const toml::basic_value<toml::discard_comments, std::map, std::deque>
+            v{{"a", 42}, {"b", "baz"}};
+
+        const auto bar = toml::get<extlib2::bar>(v);
+        BOOST_TEST(bar.a == 42);
+        BOOST_TEST(bar.b == "baz");
+
+        const toml::basic_value<toml::discard_comments, std::map, std::deque>
+            v2(bar);
+
+        BOOST_TEST(v == v2);
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_conversion_one_way)
+{
+    {
+        const toml::value v{{"a", 42}, {"b", "baz"}};
+
+        const auto baz = toml::get<extlib::baz>(v);
+        BOOST_TEST(baz.a == 42);
+        BOOST_TEST(baz.b == "baz");
+    }
+    {
+        const extlib::qux q{42, "qux"};
+        const toml::value v(q);
+
+        BOOST_TEST(toml::find<int>(v, "a")         == 42);
+        BOOST_TEST(toml::find<std::string>(v, "b") == "qux");
+    }
+
+    {
+        const toml::basic_value<toml::discard_comments, std::map> v{
+            {"a", 42}, {"b", "baz"}
+        };
+
+        const auto baz = toml::get<extlib2::baz>(v);
+        BOOST_TEST(baz.a == 42);
+        BOOST_TEST(baz.b == "baz");
+    }
+    {
+        const extlib::qux q{42, "qux"};
+        const toml::basic_value<toml::preserve_comments, std::map> v(q);
+
+        BOOST_TEST(toml::find<int>(v, "a")         == 42);
+        BOOST_TEST(toml::find<std::string>(v, "b") == "qux");
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_conversion_via_constructor)
+{
+    {
+        const toml::value v{{"a", 42}, {"b", "foobar"}};
+
+        const auto foobar = toml::get<extlib::foobar>(v);
+        BOOST_TEST(foobar.a == 42);
+        BOOST_TEST(foobar.b == "foobar");
+    }
+
+    {
+        const toml::basic_value<toml::discard_comments, std::map> v{
+            {"a", 42}, {"b", "foobar"}
+        };
+
+        const auto foobar = toml::get<extlib2::foobar>(v);
+        BOOST_TEST(foobar.a == 42);
+        BOOST_TEST(foobar.b == "foobar");
+    }
 }
 
 BOOST_AUTO_TEST_CASE(test_recursive_conversion)
 {
-    const toml::value v{
-        toml::table{{"a", 42}, {"b", "baz"}},
-        toml::table{{"a", 43}, {"b", "qux"}},
-        toml::table{{"a", 44}, {"b", "quux"}},
-        toml::table{{"a", 45}, {"b", "foobar"}},
-    };
+    {
+        const toml::value v{
+            toml::table{{"a", 42}, {"b", "baz"}},
+            toml::table{{"a", 43}, {"b", "qux"}},
+            toml::table{{"a", 44}, {"b", "quux"}},
+            toml::table{{"a", 45}, {"b", "foobar"}},
+        };
 
-    const auto foos = toml::get<std::vector<extlib::foo>>(v);
-    BOOST_CHECK_EQUAL(foos.size()  , 4ul);
-    BOOST_CHECK_EQUAL(foos.at(0).a , 42);
-    BOOST_CHECK_EQUAL(foos.at(1).a , 43);
-    BOOST_CHECK_EQUAL(foos.at(2).a , 44);
-    BOOST_CHECK_EQUAL(foos.at(3).a , 45);
+        const auto foos = toml::get<std::vector<extlib::foo>>(v);
+        BOOST_TEST(foos.size()  == 4ul);
+        BOOST_TEST(foos.at(0).a == 42);
+        BOOST_TEST(foos.at(1).a == 43);
+        BOOST_TEST(foos.at(2).a == 44);
+        BOOST_TEST(foos.at(3).a == 45);
 
-    BOOST_CHECK_EQUAL(foos.at(0).b , "baz");
-    BOOST_CHECK_EQUAL(foos.at(1).b , "qux");
-    BOOST_CHECK_EQUAL(foos.at(2).b , "quux");
-    BOOST_CHECK_EQUAL(foos.at(3).b , "foobar");
+        BOOST_TEST(foos.at(0).b == "baz");
+        BOOST_TEST(foos.at(1).b == "qux");
+        BOOST_TEST(foos.at(2).b == "quux");
+        BOOST_TEST(foos.at(3).b == "foobar");
 
-    const auto bars = toml::get<std::vector<extlib::bar>>(v);
-    BOOST_CHECK_EQUAL(bars.size()  , 4ul);
-    BOOST_CHECK_EQUAL(bars.at(0).a , 42);
-    BOOST_CHECK_EQUAL(bars.at(1).a , 43);
-    BOOST_CHECK_EQUAL(bars.at(2).a , 44);
-    BOOST_CHECK_EQUAL(bars.at(3).a , 45);
+        const auto bars = toml::get<std::vector<extlib::bar>>(v);
+        BOOST_TEST(bars.size()  == 4ul);
+        BOOST_TEST(bars.at(0).a == 42);
+        BOOST_TEST(bars.at(1).a == 43);
+        BOOST_TEST(bars.at(2).a == 44);
+        BOOST_TEST(bars.at(3).a == 45);
+
+        BOOST_TEST(bars.at(0).b == "baz");
+        BOOST_TEST(bars.at(1).b == "qux");
+        BOOST_TEST(bars.at(2).b == "quux");
+        BOOST_TEST(bars.at(3).b == "foobar");
+    }
+    {
+        const toml::value v{
+                toml::table{{"a", 42}, {"b", "baz"}},
+                toml::table{{"a", 43}, {"b", "qux"}},
+                toml::table{{"a", 44}, {"b", "quux"}},
+                toml::table{{"a", 45}, {"b", "foobar"}},
+            };
+
+        const auto foos = toml::get<std::vector<extlib2::foo>>(v);
+        BOOST_TEST(foos.size()  == 4ul);
+        BOOST_TEST(foos.at(0).a == 42);
+        BOOST_TEST(foos.at(1).a == 43);
+        BOOST_TEST(foos.at(2).a == 44);
+        BOOST_TEST(foos.at(3).a == 45);
+
+        BOOST_TEST(foos.at(0).b == "baz");
+        BOOST_TEST(foos.at(1).b == "qux");
+        BOOST_TEST(foos.at(2).b == "quux");
+        BOOST_TEST(foos.at(3).b == "foobar");
+
+        const auto bars = toml::get<std::vector<extlib2::bar>>(v);
+        BOOST_TEST(bars.size()  == 4ul);
+        BOOST_TEST(bars.at(0).a == 42);
+        BOOST_TEST(bars.at(1).a == 43);
+        BOOST_TEST(bars.at(2).a == 44);
+        BOOST_TEST(bars.at(3).a == 45);
+
+        BOOST_TEST(bars.at(0).b == "baz");
+        BOOST_TEST(bars.at(1).b == "qux");
+        BOOST_TEST(bars.at(2).b == "quux");
+        BOOST_TEST(bars.at(3).b == "foobar");
+    }
+
+    {
+        const toml::basic_value<toml::discard_comments, std::map, std::deque>
+            v{
+                toml::table{{"a", 42}, {"b", "baz"}},
+                toml::table{{"a", 43}, {"b", "qux"}},
+                toml::table{{"a", 44}, {"b", "quux"}},
+                toml::table{{"a", 45}, {"b", "foobar"}}
+            };
+
+        const auto foos = toml::get<std::vector<extlib2::foo>>(v);
+        BOOST_TEST(foos.size()  == 4ul);
+        BOOST_TEST(foos.at(0).a == 42);
+        BOOST_TEST(foos.at(1).a == 43);
+        BOOST_TEST(foos.at(2).a == 44);
+        BOOST_TEST(foos.at(3).a == 45);
+
+        BOOST_TEST(foos.at(0).b == "baz");
+        BOOST_TEST(foos.at(1).b == "qux");
+        BOOST_TEST(foos.at(2).b == "quux");
+        BOOST_TEST(foos.at(3).b == "foobar");
+
+        const auto bars = toml::get<std::vector<extlib2::bar>>(v);
+        BOOST_TEST(bars.size()  == 4ul);
+        BOOST_TEST(bars.at(0).a == 42);
+        BOOST_TEST(bars.at(1).a == 43);
+        BOOST_TEST(bars.at(2).a == 44);
+        BOOST_TEST(bars.at(3).a == 45);
+
+        BOOST_TEST(bars.at(0).b == "baz");
+        BOOST_TEST(bars.at(1).b == "qux");
+        BOOST_TEST(bars.at(2).b == "quux");
+        BOOST_TEST(bars.at(3).b == "foobar");
+    }
+
+    // via constructor
+    {
+        const toml::value v{
+                toml::table{{"a", 42}, {"b", "baz"}},
+                toml::table{{"a", 43}, {"b", "qux"}},
+                toml::table{{"a", 44}, {"b", "quux"}},
+                toml::table{{"a", 45}, {"b", "foobar"}}
+            };
+
+        {
+            const auto foobars = toml::get<std::vector<extlib::foobar>>(v);
+            BOOST_TEST(foobars.size()  == 4ul);
+            BOOST_TEST(foobars.at(0).a == 42);
+            BOOST_TEST(foobars.at(1).a == 43);
+            BOOST_TEST(foobars.at(2).a == 44);
+            BOOST_TEST(foobars.at(3).a == 45);
+
+            BOOST_TEST(foobars.at(0).b == "baz");
+            BOOST_TEST(foobars.at(1).b == "qux");
+            BOOST_TEST(foobars.at(2).b == "quux");
+            BOOST_TEST(foobars.at(3).b == "foobar");
+        }
+        {
+            const auto foobars = toml::get<std::vector<extlib2::foobar>>(v);
+            BOOST_TEST(foobars.size()  == 4ul);
+            BOOST_TEST(foobars.at(0).a == 42);
+            BOOST_TEST(foobars.at(1).a == 43);
+            BOOST_TEST(foobars.at(2).a == 44);
+            BOOST_TEST(foobars.at(3).a == 45);
+
+            BOOST_TEST(foobars.at(0).b == "baz");
+            BOOST_TEST(foobars.at(1).b == "qux");
+            BOOST_TEST(foobars.at(2).b == "quux");
+            BOOST_TEST(foobars.at(3).b == "foobar");
+        }
+    }
+    {
+        const toml::basic_value<toml::discard_comments, std::map, std::deque>
+            v{
+                toml::table{{"a", 42}, {"b", "baz"}},
+                toml::table{{"a", 43}, {"b", "qux"}},
+                toml::table{{"a", 44}, {"b", "quux"}},
+                toml::table{{"a", 45}, {"b", "foobar"}}
+            };
+
+        const auto foobars = toml::get<std::vector<extlib2::foobar>>(v);
+        BOOST_TEST(foobars.size()  == 4ul);
+        BOOST_TEST(foobars.at(0).a == 42);
+        BOOST_TEST(foobars.at(1).a == 43);
+        BOOST_TEST(foobars.at(2).a == 44);
+        BOOST_TEST(foobars.at(3).a == 45);
+
+        BOOST_TEST(foobars.at(0).b == "baz");
+        BOOST_TEST(foobars.at(1).b == "qux");
+        BOOST_TEST(foobars.at(2).b == "quux");
+        BOOST_TEST(foobars.at(3).b == "foobar");
+    }
+
+    // via constructor
+    {
+        const toml::value v{
+                {"0", toml::table{{"a", 42}, {"b", "baz"}}},
+                {"1", toml::table{{"a", 43}, {"b", "qux"}}},
+                {"2", toml::table{{"a", 44}, {"b", "quux"}}},
+                {"3", toml::table{{"a", 45}, {"b", "foobar"}}}
+            };
+
+        {
+            const auto foobars = toml::get<std::map<std::string, extlib::foobar>>(v);
+            BOOST_TEST(foobars.size()  == 4ul);
+            BOOST_TEST(foobars.at("0").a == 42);
+            BOOST_TEST(foobars.at("1").a == 43);
+            BOOST_TEST(foobars.at("2").a == 44);
+            BOOST_TEST(foobars.at("3").a == 45);
+
+            BOOST_TEST(foobars.at("0").b == "baz");
+            BOOST_TEST(foobars.at("1").b == "qux");
+            BOOST_TEST(foobars.at("2").b == "quux");
+            BOOST_TEST(foobars.at("3").b == "foobar");
+        }
+        {
+            const auto foobars = toml::get<std::map<std::string, extlib2::foobar>>(v);
+            BOOST_TEST(foobars.size()  == 4ul);
+            BOOST_TEST(foobars.at("0").a == 42);
+            BOOST_TEST(foobars.at("1").a == 43);
+            BOOST_TEST(foobars.at("2").a == 44);
+            BOOST_TEST(foobars.at("3").a == 45);
+
+            BOOST_TEST(foobars.at("0").b == "baz");
+            BOOST_TEST(foobars.at("1").b == "qux");
+            BOOST_TEST(foobars.at("2").b == "quux");
+            BOOST_TEST(foobars.at("3").b == "foobar");
+        }
+    }
+    {
+        const toml::basic_value<toml::discard_comments, std::map, std::deque>
+            v{
+                {"0", toml::table{{"a", 42}, {"b", "baz"}}},
+                {"1", toml::table{{"a", 43}, {"b", "qux"}}},
+                {"2", toml::table{{"a", 44}, {"b", "quux"}}},
+                {"3", toml::table{{"a", 45}, {"b", "foobar"}}}
+            };
+
+        const auto foobars = toml::get<std::map<std::string, extlib::foobar>>(v);
+        BOOST_TEST(foobars.size()  == 4ul);
+        BOOST_TEST(foobars.at("0").a == 42);
+        BOOST_TEST(foobars.at("1").a == 43);
+        BOOST_TEST(foobars.at("2").a == 44);
+        BOOST_TEST(foobars.at("3").a == 45);
+
+        BOOST_TEST(foobars.at("0").b == "baz");
+        BOOST_TEST(foobars.at("1").b == "qux");
+        BOOST_TEST(foobars.at("2").b == "quux");
+        BOOST_TEST(foobars.at("3").b == "foobar");
+    }
 
-    BOOST_CHECK_EQUAL(bars.at(0).b , "baz");
-    BOOST_CHECK_EQUAL(bars.at(1).b , "qux");
-    BOOST_CHECK_EQUAL(bars.at(2).b , "quux");
-    BOOST_CHECK_EQUAL(bars.at(3).b , "foobar");
 }
+

tests/test_find.cpp

@@ -0,0 +1,833 @@
+#define BOOST_TEST_MODULE "test_find"
+
+#ifdef UNITTEST_FRAMEWORK_LIBRARY_EXIST
+#include <boost/test/unit_test.hpp>
+#else
+#define BOOST_TEST_NO_LIB
+#include <boost/test/included/unit_test.hpp>
+#endif
+
+#include <toml.hpp>
+#include <map>
+#include <unordered_map>
+#include <list>
+#include <deque>
+#include <array>
+#if __cplusplus >= 201703L
+#include <string_view>
+#endif
+#include <tuple>
+
+using test_value_types = std::tuple<
+    toml::value,
+    toml::basic_value<toml::preserve_comments>,
+    toml::basic_value<toml::discard_comments,  std::map, std::deque>,
+    toml::basic_value<toml::preserve_comments, std::map, std::deque>
+    >;
+
+BOOST_AUTO_TEST_CASE(test_find_throws)
+{
+    // -----------------------------------------------------------------------
+    // const-reference version
+    {
+        // value is not a table
+        const toml::value v(true);
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(v, "key"), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not the expected type
+        const toml::value v{{"key", 42}};
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(v, "key"), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not found
+        const toml::value v{{"key", 42}};
+        BOOST_CHECK_THROW(toml::find<toml::integer>(v, "different_key"),
+                          std::out_of_range);
+    }
+    {
+        // the positive control.
+        const toml::value v{{"key", 42}};
+        BOOST_TEST(42 == toml::find<int>(v, "key"));
+    }
+
+    // -----------------------------------------------------------------------
+    // reference version
+    {
+        // value is not a table
+        toml::value v(true);
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(v, "key"), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not the expected type
+        toml::value v{{"key", 42}};
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(v, "key"), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not found
+        toml::value v{{"key", 42}};
+        BOOST_CHECK_THROW(toml::find<toml::integer>(v, "different_key"),
+                          std::out_of_range);
+    }
+    {
+        // the positive control.
+        toml::value v{{"key", 42}};
+        BOOST_TEST(42 == toml::find<int>(v, "key"));
+    }
+
+    // -----------------------------------------------------------------------
+    // move version
+
+    {
+        // value is not a table
+        toml::value v(true);
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(std::move(v), "key"), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not the expected type
+        toml::value v{{"key", 42}};
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(std::move(v), "key"), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not found
+        toml::value v{{"key", 42}};
+        BOOST_CHECK_THROW(toml::find<toml::integer>(std::move(v), "different_key"),
+                          std::out_of_range);
+    }
+    {
+        // the positive control.
+        toml::value v{{"key", 42}};
+        BOOST_TEST(42 == toml::find<int>(std::move(v), "key"));
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_find_array_throws)
+{
+    // -----------------------------------------------------------------------
+    // const-reference version
+    {
+        // value is not an array
+        const toml::value v(true);
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(v, 0), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not the expected type
+        const toml::value v{1, 2, 3, 4, 5};
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(v, 0), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not found
+        const toml::value v{1, 2, 3, 4, 5};
+        BOOST_CHECK_THROW(toml::find<toml::integer>(v, 6), std::out_of_range);
+    }
+    {
+        // the positive control.
+        const toml::value v{1, 2, 3, 4, 5};
+        BOOST_TEST(3 == toml::find<int>(v, 2));
+    }
+
+    // -----------------------------------------------------------------------
+    // non-const reference version
+    {
+        // value is not an array
+        toml::value v(true);
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(v, 0), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not the expected type
+        toml::value v{1, 2, 3, 4, 5};
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(v, 0), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not found
+        toml::value v{1, 2, 3, 4, 5};
+        BOOST_CHECK_THROW(toml::find<toml::integer>(v, 6), std::out_of_range);
+    }
+    {
+        // the positive control.
+        toml::value v{1, 2, 3, 4, 5};
+        BOOST_TEST(3 == toml::find<int>(v, 2));
+    }
+
+    // -----------------------------------------------------------------------
+    // move version
+    {
+        // value is not an array
+        toml::value v(true);
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(std::move(v), 0), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not the expected type
+        toml::value v{1, 2, 3, 4, 5};
+        BOOST_CHECK_THROW(toml::find<toml::boolean>(std::move(v), 0), toml::type_error);
+    }
+    {
+        // the value corresponding to the key is not found
+        toml::value v{1, 2, 3, 4, 5};
+        BOOST_CHECK_THROW(toml::find<toml::integer>(std::move(v), 6), std::out_of_range);
+    }
+    {
+        // the positive control.
+        toml::value v{1, 2, 3, 4, 5};
+        BOOST_TEST(3 == toml::find<int>(std::move(v), 2));
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_find_recursive)
+{
+    // recursively search tables
+    {
+        toml::value v{
+            {"a", {
+                {"b", {
+                    {"c", {
+                        {"d", 42}
+                    }}
+                }}
+            }}
+        };
+        BOOST_TEST(42 == toml::find<int>(v, "a", "b", "c", "d"));
+
+        // reference that can be used to modify the content
+        auto& num = toml::find<toml::integer>(v, "a", "b", "c", "d");
+        num = 54;
+        BOOST_TEST(54 == toml::find<int>(v, "a", "b", "c", "d"));
+
+        const std::string a("a"), b("b"), c("c"), d("d");
+        auto& num2 = toml::find<toml::integer>(v, a, b, c, d);
+        num2 = 42;
+        BOOST_TEST(42 == toml::find<int>(v, a, b, c, d));
+
+        auto num3 = toml::find<toml::integer>(v, a, "b", c, "d");
+        BOOST_TEST(42 == num3);
+
+        auto num4 = toml::find<toml::integer>(std::move(v), a, b, c, d);
+        BOOST_TEST(42 == num4);
+    }
+    // recursively search arrays
+    {
+        toml::value v{
+            toml::array{"array", "of", "string"},
+            toml::array{toml::array{1, 2, 3}, toml::array{3.14, 2.71}}
+        };
+        BOOST_TEST("array"  == toml::find<std::string>(v, 0, 0));
+        BOOST_TEST("of"     == toml::find<std::string>(v, 0, 1));
+        BOOST_TEST("string" == toml::find<std::string>(v, 0, 2));
+
+        BOOST_TEST(1 == toml::find<int>(v, 1, 0, 0));
+        BOOST_TEST(2 == toml::find<int>(v, 1, 0, 1));
+        BOOST_TEST(3 == toml::find<int>(v, 1, 0, 2));
+
+        BOOST_TEST(3.14 == toml::find<double>(v, 1, 1, 0));
+        BOOST_TEST(2.71 == toml::find<double>(v, 1, 1, 1));
+
+        // reference that can be used to modify the content
+        auto& num = toml::find<toml::integer>(v, 1, 0, 2);
+        num = 42;
+        BOOST_TEST( 1 == toml::find<int>(v, 1, 0, 0));
+        BOOST_TEST( 2 == toml::find<int>(v, 1, 0, 1));
+        BOOST_TEST(42 == toml::find<int>(v, 1, 0, 2));
+
+        // move value
+        auto num2 = toml::find<toml::integer>(std::move(v), 1, 0, 2);
+        BOOST_TEST(42 == num2);
+    }
+    // recursively search mixtures
+    {
+        toml::value v = toml::table{{"array", toml::array{
+                toml::array{1,   2,   3},
+                toml::array{
+                    toml::table{{"foo", "bar"}, {"baz", "qux"}},
+                    toml::table{{"pi",   3.14}, {"e",    2.71}}
+                }}
+            }};
+
+        BOOST_TEST(1 == toml::find<int>(v, "array", 0, 0));
+        BOOST_TEST(2 == toml::find<int>(v, "array", 0, 1));
+        BOOST_TEST(3 == toml::find<int>(v, "array", 0, 2));
+
+        BOOST_TEST("bar" == toml::find<std::string>(v, "array", 1, 0, "foo"));
+        BOOST_TEST("qux" == toml::find<std::string>(v, "array", 1, 0, "baz"));
+
+        BOOST_TEST(3.14 == toml::find<double>(v, "array", 1, 1, "pi"));
+        BOOST_TEST(2.71 == toml::find<double>(v, "array", 1, 1, "e"));
+
+        const std::string ar("array");
+        const auto ar_c = "array";
+
+        const std::string pi("pi");
+        const auto pi_c = "pi";
+
+        BOOST_TEST(3.14 == toml::find<double>(v, ar, 1, 1, "pi"));
+        BOOST_TEST(3.14 == toml::find<double>(v, ar, 1, 1, pi));
+        BOOST_TEST(3.14 == toml::find<double>(v, ar, 1, 1, pi_c));
+
+        BOOST_TEST(3.14 == toml::find<double>(v, ar_c, 1, 1, "pi"));
+        BOOST_TEST(3.14 == toml::find<double>(v, ar_c, 1, 1, pi));
+        BOOST_TEST(3.14 == toml::find<double>(v, ar_c, 1, 1, pi_c));
+
+        BOOST_TEST(3.14 == toml::find<double>(v, "array", 1, 1, pi));
+        BOOST_TEST(3.14 == toml::find<double>(v, "array", 1, 1, pi_c));
+    }
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_exact, value_type, test_value_types)
+{
+    {
+        value_type v{{"key", true}};
+        BOOST_TEST(true == toml::find<toml::boolean>(v, "key"));
+
+        toml::find<toml::boolean>(v, "key") = false;
+        BOOST_TEST(false == toml::find<toml::boolean>(v, "key"));
+
+        const auto moved = toml::find<toml::boolean>(std::move(v), "key");
+        BOOST_TEST(false == moved);
+    }
+    {
+        value_type v{{"key", 42}};
+        BOOST_TEST(toml::integer(42) == toml::find<toml::integer>(v, "key"));
+
+        toml::find<toml::integer>(v, "key") = 54;
+        BOOST_TEST(toml::integer(54) == toml::find<toml::integer>(v, "key"));
+
+        const auto moved = toml::find<toml::integer>(std::move(v), "key");
+        BOOST_TEST(toml::integer(54) == moved);
+    }
+    {
+        value_type v{{"key", 3.14}};
+        BOOST_TEST(toml::floating(3.14) == toml::find<toml::floating>(v, "key"));
+
+        toml::find<toml::floating>(v, "key") = 2.71;
+        BOOST_TEST(toml::floating(2.71) == toml::find<toml::floating>(v, "key"));
+
+        const auto moved = toml::find<toml::floating>(std::move(v), "key");
+        BOOST_TEST(toml::floating(2.71) == moved);
+    }
+    {
+        value_type v{{"key", "foo"}};
+        BOOST_TEST(toml::string("foo", toml::string_t::basic) ==
+                          toml::find<toml::string>(v, "key"));
+
+        toml::find<toml::string>(v, "key").str += "bar";
+        BOOST_TEST(toml::string("foobar", toml::string_t::basic) ==
+                          toml::find<toml::string>(v, "key"));
+
+        const auto moved = toml::find<toml::string>(std::move(v), "key");
+        BOOST_TEST(toml::string("foobar", toml::string_t::basic) == moved);
+    }
+    {
+        value_type v{{"key", value_type("foo", toml::string_t::literal)}};
+        BOOST_TEST(toml::string("foo", toml::string_t::literal) ==
+                          toml::find<toml::string>(v, "key"));
+
+        toml::find<toml::string>(v, "key").str += "bar";
+        BOOST_TEST(toml::string("foobar", toml::string_t::literal) ==
+                          toml::find<toml::string>(v, "key"));
+
+        const auto moved = toml::find<toml::string>(std::move(v), "key");
+        BOOST_TEST(toml::string("foobar", toml::string_t::literal) == moved);
+    }
+    {
+        toml::local_date d(2018, toml::month_t::Apr, 22);
+        value_type v{{"key", d}};
+        BOOST_CHECK(d == toml::find<toml::local_date>(v, "key"));
+
+        toml::find<toml::local_date>(v, "key").year = 2017;
+        d.year = 2017;
+        BOOST_CHECK(d == toml::find<toml::local_date>(v, "key"));
+
+        const auto moved = toml::find<toml::local_date>(std::move(v), "key");
+        BOOST_CHECK(d == moved);
+    }
+    {
+        toml::local_time t(12, 30, 45);
+        value_type v{{"key", t}};
+        BOOST_CHECK(t == toml::find<toml::local_time>(v, "key"));
+
+        toml::find<toml::local_time>(v, "key").hour = 9;
+        t.hour = 9;
+        BOOST_CHECK(t == toml::find<toml::local_time>(v, "key"));
+
+        const auto moved = toml::find<toml::local_time>(std::move(v), "key");
+        BOOST_CHECK(t == moved);
+    }
+    {
+        toml::local_datetime dt(toml::local_date(2018, toml::month_t::Apr, 22),
+                                toml::local_time(12, 30, 45));
+        value_type v{{"key", dt}};
+        BOOST_CHECK(dt == toml::find<toml::local_datetime>(v, "key"));
+
+        toml::find<toml::local_datetime>(v, "key").date.year = 2017;
+        dt.date.year = 2017;
+        BOOST_CHECK(dt == toml::find<toml::local_datetime>(v, "key"));
+
+        const auto moved = toml::find<toml::local_datetime>(std::move(v), "key");
+        BOOST_CHECK(dt == moved);
+    }
+    {
+        toml::offset_datetime dt(toml::local_datetime(
+                    toml::local_date(2018, toml::month_t::Apr, 22),
+                    toml::local_time(12, 30, 45)), toml::time_offset(9, 0));
+        value_type v{{"key", dt}};
+        BOOST_CHECK(dt == toml::find<toml::offset_datetime>(v, "key"));
+
+        toml::find<toml::offset_datetime>(v, "key").date.year = 2017;
+        dt.date.year = 2017;
+        BOOST_CHECK(dt == toml::find<toml::offset_datetime>(v, "key"));
+
+        const auto moved = toml::find<toml::offset_datetime>(std::move(v), "key");
+        BOOST_CHECK(dt == moved);
+    }
+    {
+        typename value_type::array_type vec;
+        vec.push_back(value_type(42));
+        vec.push_back(value_type(54));
+        value_type v{{"key", vec}};
+
+        const bool result1 = (vec == toml::find<typename value_type::array_type>(v, "key"));
+        BOOST_CHECK(result1);
+
+        toml::find<typename value_type::array_type>(v, "key").push_back(value_type(123));
+        vec.push_back(value_type(123));
+
+        const bool result2 = (vec == toml::find<typename value_type::array_type>(v, "key"));
+        BOOST_CHECK(result2);
+
+        const auto moved = toml::find<typename value_type::array_type>(std::move(v), "key");
+        const bool result3 = (vec == moved);
+        BOOST_CHECK(result3);
+    }
+    {
+        typename value_type::table_type tab;
+        tab["key1"] = value_type(42);
+        tab["key2"] = value_type(3.14);
+        value_type v{{"key", tab}};
+        const bool result1 = (tab == toml::find<typename value_type::table_type>(v, "key"));
+        BOOST_CHECK(result1);
+
+        toml::find<typename value_type::table_type>(v, "key")["key3"] = value_type(123);
+        tab["key3"] = value_type(123);
+        const bool result2 = (tab == toml::find<typename value_type::table_type>(v, "key"));
+        BOOST_CHECK(result2);
+
+        const auto moved = toml::find<typename value_type::table_type>(std::move(v), "key");
+        const bool result3 = (tab == moved);
+        BOOST_CHECK(result3);
+    }
+    {
+        value_type v1(42);
+        value_type v{{"key", v1}};
+        BOOST_CHECK(v1 == toml::find(v, "key"));
+
+        value_type v2(54);
+        toml::find(v, "key") = v2;
+        BOOST_CHECK(v2 == toml::find(v, "key"));
+
+        const auto moved = toml::find(std::move(v), "key");
+        BOOST_CHECK(v2 == moved);
+    }
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_integer_type, value_type, test_value_types)
+{
+    {
+        value_type v{{"key", 42}};
+        BOOST_TEST(int(42)           == toml::find<int          >(v, "key"));
+        BOOST_TEST(short(42)         == toml::find<short        >(v, "key"));
+        BOOST_TEST(char(42)          == toml::find<char         >(v, "key"));
+        BOOST_TEST(unsigned(42)      == toml::find<unsigned     >(v, "key"));
+        BOOST_TEST(long(42)          == toml::find<long         >(v, "key"));
+        BOOST_TEST(std::int64_t(42)  == toml::find<std::int64_t >(v, "key"));
+        BOOST_TEST(std::uint64_t(42) == toml::find<std::uint64_t>(v, "key"));
+        BOOST_TEST(std::int16_t(42)  == toml::find<std::int16_t >(v, "key"));
+        BOOST_TEST(std::uint16_t(42) == toml::find<std::uint16_t>(v, "key"));
+        BOOST_TEST(std::uint16_t(42) == toml::find<std::uint16_t>(std::move(v), "key"));
+    }
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_floating_type, value_type, test_value_types)
+{
+    {
+        value_type v{{"key", 3.14}};
+        const double ref(3.14);
+        BOOST_TEST(static_cast<float      >(ref) == toml::find<float      >(v, "key"));
+        BOOST_TEST(                         ref  == toml::find<double     >(v, "key"));
+        BOOST_TEST(static_cast<long double>(ref) == toml::find<long double>(v, "key"));
+        BOOST_TEST(static_cast<float      >(ref) == toml::find<float      >(std::move(v), "key"));
+    }
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_string_type, value_type, test_value_types)
+{
+    {
+        value_type v{{"key", toml::string("foo", toml::string_t::basic)}};
+        BOOST_TEST("foo" == toml::find<std::string>(v, "key"));
+        toml::find<std::string>(v, "key") += "bar";
+        BOOST_TEST("foobar" == toml::find<std::string>(v, "key"));
+    }
+    {
+        value_type v{{"key", toml::string("foo", toml::string_t::literal)}};
+        BOOST_TEST("foo" == toml::find<std::string>(v, "key"));
+        toml::find<std::string>(v, "key") += "bar";
+        BOOST_TEST("foobar" == toml::find<std::string>(v, "key"));
+    }
+    {
+        value_type v{{"key", toml::string("foo", toml::string_t::literal)}};
+        const auto moved = toml::find<std::string>(std::move(v), "key");
+        BOOST_TEST("foo" == moved);
+    }
+
+#if __cplusplus >= 201703L
+    {
+        value_type v{{"key", toml::string("foo", toml::string_t::basic)}};
+        BOOST_TEST("foo" == toml::find<std::string_view>(v, "key"));
+    }
+    {
+        value_type v{{"key", toml::string("foo", toml::string_t::literal)}};
+        BOOST_TEST("foo" == toml::find<std::string_view>(v, "key"));
+    }
+#endif
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_toml_array, value_type, test_value_types)
+{
+    value_type v{{"key", {42, 54, 69, 72}}};
+
+    const std::vector<int>         vec = toml::find<std::vector<int>>(v, "key");
+    const std::list<short>         lst = toml::find<std::list<short>>(v, "key");
+    const std::deque<std::int64_t> deq = toml::find<std::deque<std::int64_t>>(v, "key");
+
+    BOOST_TEST(42 == vec.at(0));
+    BOOST_TEST(54 == vec.at(1));
+    BOOST_TEST(69 == vec.at(2));
+    BOOST_TEST(72 == vec.at(3));
+
+    std::list<short>::const_iterator iter = lst.begin();
+    BOOST_TEST(static_cast<short>(42) == *(iter++));
+    BOOST_TEST(static_cast<short>(54) == *(iter++));
+    BOOST_TEST(static_cast<short>(69) == *(iter++));
+    BOOST_TEST(static_cast<short>(72) == *(iter++));
+
+    BOOST_TEST(static_cast<std::int64_t>(42) == deq.at(0));
+    BOOST_TEST(static_cast<std::int64_t>(54) == deq.at(1));
+    BOOST_TEST(static_cast<std::int64_t>(69) == deq.at(2));
+    BOOST_TEST(static_cast<std::int64_t>(72) == deq.at(3));
+
+    std::array<int, 4> ary = toml::find<std::array<int, 4>>(v, "key");
+    BOOST_TEST(42 == ary.at(0));
+    BOOST_TEST(54 == ary.at(1));
+    BOOST_TEST(69 == ary.at(2));
+    BOOST_TEST(72 == ary.at(3));
+
+    std::tuple<int, short, unsigned, long> tpl =
+        toml::find<std::tuple<int, short, unsigned, long>>(v, "key");
+    BOOST_TEST(                      42  == std::get<0>(tpl));
+    BOOST_TEST(static_cast<short   >(54) == std::get<1>(tpl));
+    BOOST_TEST(static_cast<unsigned>(69) == std::get<2>(tpl));
+    BOOST_TEST(static_cast<long    >(72) == std::get<3>(tpl));
+
+    value_type p{{"key", {3.14, 2.71}}};
+    std::pair<double, double> pr = toml::find<std::pair<double, double> >(p, "key");
+    BOOST_TEST(3.14 == pr.first);
+    BOOST_TEST(2.71 == pr.second);
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_move_toml_array, value_type, test_value_types)
+{
+    value_type v1{{"key", {42, 54, 69, 72}}};
+    value_type v2{{"key", {42, 54, 69, 72}}};
+    value_type v3{{"key", {42, 54, 69, 72}}};
+    value_type v4{{"key", {42, 54, 69, 72}}};
+    value_type v5{{"key", {42, 54, 69, 72}}};
+
+    const std::vector<int>         vec = toml::find<std::vector<int>>(std::move(v1), "key");
+    const std::list<short>         lst = toml::find<std::list<short>>(std::move(v2), "key");
+    const std::deque<std::int64_t> deq = toml::find<std::deque<std::int64_t>>(std::move(v3), "key");
+
+    BOOST_TEST(42 == vec.at(0));
+    BOOST_TEST(54 == vec.at(1));
+    BOOST_TEST(69 == vec.at(2));
+    BOOST_TEST(72 == vec.at(3));
+
+    std::list<short>::const_iterator iter = lst.begin();
+    BOOST_TEST(static_cast<short>(42) == *(iter++));
+    BOOST_TEST(static_cast<short>(54) == *(iter++));
+    BOOST_TEST(static_cast<short>(69) == *(iter++));
+    BOOST_TEST(static_cast<short>(72) == *(iter++));
+
+    BOOST_TEST(static_cast<std::int64_t>(42) == deq.at(0));
+    BOOST_TEST(static_cast<std::int64_t>(54) == deq.at(1));
+    BOOST_TEST(static_cast<std::int64_t>(69) == deq.at(2));
+    BOOST_TEST(static_cast<std::int64_t>(72) == deq.at(3));
+
+    std::array<int, 4> ary = toml::find<std::array<int, 4>>(std::move(v4), "key");
+    BOOST_TEST(42 == ary.at(0));
+    BOOST_TEST(54 == ary.at(1));
+    BOOST_TEST(69 == ary.at(2));
+    BOOST_TEST(72 == ary.at(3));
+
+    std::tuple<int, short, unsigned, long> tpl =
+        toml::find<std::tuple<int, short, unsigned, long>>(std::move(v5), "key");
+    BOOST_TEST(                      42  == std::get<0>(tpl));
+    BOOST_TEST(static_cast<short   >(54) == std::get<1>(tpl));
+    BOOST_TEST(static_cast<unsigned>(69) == std::get<2>(tpl));
+    BOOST_TEST(static_cast<long    >(72) == std::get<3>(tpl));
+
+    value_type p{{"key", {3.14, 2.71}}};
+    std::pair<double, double> pr = toml::find<std::pair<double, double> >(std::move(p), "key");
+    BOOST_TEST(3.14 == pr.first);
+    BOOST_TEST(2.71 == pr.second);
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_toml_array_of_array, value_type, test_value_types)
+{
+    value_type v1{42, 54, 69, 72};
+    value_type v2{"foo", "bar", "baz"};
+    value_type v{{"key", {v1, v2}}};
+
+    std::pair<std::vector<int>, std::vector<std::string>> p =
+        toml::find<std::pair<std::vector<int>, std::vector<std::string>>>(v, "key");
+
+    BOOST_TEST(p.first.at(0) == 42);
+    BOOST_TEST(p.first.at(1) == 54);
+    BOOST_TEST(p.first.at(2) == 69);
+    BOOST_TEST(p.first.at(3) == 72);
+
+    BOOST_TEST(p.second.at(0) == "foo");
+    BOOST_TEST(p.second.at(1) == "bar");
+    BOOST_TEST(p.second.at(2) == "baz");
+
+    std::tuple<std::vector<int>, std::vector<std::string>> t =
+        toml::find<std::tuple<std::vector<int>, std::vector<std::string>>>(v, "key");
+
+    BOOST_TEST(std::get<0>(t).at(0) == 42);
+    BOOST_TEST(std::get<0>(t).at(1) == 54);
+    BOOST_TEST(std::get<0>(t).at(2) == 69);
+    BOOST_TEST(std::get<0>(t).at(3) == 72);
+
+    BOOST_TEST(std::get<1>(t).at(0) == "foo");
+    BOOST_TEST(std::get<1>(t).at(1) == "bar");
+    BOOST_TEST(std::get<1>(t).at(2) == "baz");
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_move_toml_array_of_array, value_type, test_value_types)
+{
+    value_type a1{42, 54, 69, 72};
+    value_type a2{"foo", "bar", "baz"};
+    value_type v1{{"key", {a1, a2}}};
+    value_type v2{{"key", {a1, a2}}};
+
+    std::pair<std::vector<int>, std::vector<std::string>> p =
+        toml::find<std::pair<std::vector<int>, std::vector<std::string>>>(std::move(v1), "key");
+
+    BOOST_TEST(p.first.at(0) == 42);
+    BOOST_TEST(p.first.at(1) == 54);
+    BOOST_TEST(p.first.at(2) == 69);
+    BOOST_TEST(p.first.at(3) == 72);
+
+    BOOST_TEST(p.second.at(0) == "foo");
+    BOOST_TEST(p.second.at(1) == "bar");
+    BOOST_TEST(p.second.at(2) == "baz");
+
+    std::tuple<std::vector<int>, std::vector<std::string>> t =
+        toml::find<std::tuple<std::vector<int>, std::vector<std::string>>>(std::move(v2), "key");
+
+    BOOST_TEST(std::get<0>(t).at(0) == 42);
+    BOOST_TEST(std::get<0>(t).at(1) == 54);
+    BOOST_TEST(std::get<0>(t).at(2) == 69);
+    BOOST_TEST(std::get<0>(t).at(3) == 72);
+
+    BOOST_TEST(std::get<1>(t).at(0) == "foo");
+    BOOST_TEST(std::get<1>(t).at(1) == "bar");
+    BOOST_TEST(std::get<1>(t).at(2) == "baz");
+}
+
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_toml_table, value_type, test_value_types)
+{
+    {
+        value_type v1{{"key", {
+                {"key1", 1}, {"key2", 2}, {"key3", 3}, {"key4", 4}
+            }}};
+        const auto v = toml::find<std::map<std::string, int>>(v1, "key");
+        BOOST_TEST(v.at("key1") == 1);
+        BOOST_TEST(v.at("key2") == 2);
+        BOOST_TEST(v.at("key3") == 3);
+        BOOST_TEST(v.at("key4") == 4);
+    }
+    {
+        value_type v1{{"key", {
+                {"key1", 1}, {"key2", 2}, {"key3", 3}, {"key4", 4}
+            }}};
+        const auto v = toml::find<std::map<std::string, int>>(std::move(v1), "key");
+        BOOST_TEST(v.at("key1") == 1);
+        BOOST_TEST(v.at("key2") == 2);
+        BOOST_TEST(v.at("key3") == 3);
+        BOOST_TEST(v.at("key4") == 4);
+    }
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_toml_local_date, value_type, test_value_types)
+{
+    {
+        value_type v1{{"key", toml::local_date{2018, toml::month_t::Apr, 1}}};
+        const auto date = std::chrono::system_clock::to_time_t(
+                toml::find<std::chrono::system_clock::time_point>(v1, "key"));
+
+        std::tm t;
+        t.tm_year = 2018 - 1900;
+        t.tm_mon  = 4    - 1;
+        t.tm_mday = 1;
+        t.tm_hour = 0;
+        t.tm_min  = 0;
+        t.tm_sec  = 0;
+        t.tm_isdst = -1;
+        const auto c = std::mktime(&t);
+        BOOST_TEST(c == date);
+    }
+    {
+        value_type v1{{"key", toml::local_date{2018, toml::month_t::Apr, 1}}};
+        const auto date = std::chrono::system_clock::to_time_t(
+                toml::find<std::chrono::system_clock::time_point>(std::move(v1), "key"));
+
+        std::tm t;
+        t.tm_year = 2018 - 1900;
+        t.tm_mon  = 4    - 1;
+        t.tm_mday = 1;
+        t.tm_hour = 0;
+        t.tm_min  = 0;
+        t.tm_sec  = 0;
+        t.tm_isdst = -1;
+        const auto c = std::mktime(&t);
+        BOOST_TEST(c == date);
+    }
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_toml_local_time, value_type, test_value_types)
+{
+    {
+        value_type v1{{"key", toml::local_time{12, 30, 45}}};
+        const auto time = toml::find<std::chrono::seconds>(v1, "key");
+        BOOST_CHECK(time == std::chrono::hours(12) +
+                            std::chrono::minutes(30) + std::chrono::seconds(45));
+    }
+    {
+        value_type v1{{"key", toml::local_time{12, 30, 45}}};
+        const auto time = toml::find<std::chrono::seconds>(std::move(v1), "key");
+        BOOST_CHECK(time == std::chrono::hours(12) +
+                            std::chrono::minutes(30) + std::chrono::seconds(45));
+    }
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_toml_local_datetime, value_type, test_value_types)
+{
+    {
+        value_type v1{{"key", toml::local_datetime(
+                    toml::local_date{2018, toml::month_t::Apr, 1},
+                    toml::local_time{12, 30, 45})}};
+
+        const auto date = std::chrono::system_clock::to_time_t(
+                toml::find<std::chrono::system_clock::time_point>(v1, "key"));
+        std::tm t;
+        t.tm_year = 2018 - 1900;
+        t.tm_mon  = 4    - 1;
+        t.tm_mday = 1;
+        t.tm_hour = 12;
+        t.tm_min  = 30;
+        t.tm_sec  = 45;
+        t.tm_isdst = -1;
+        const auto c = std::mktime(&t);
+        BOOST_TEST(c == date);
+    }
+    {
+        value_type v1{{"key", toml::local_datetime(
+                    toml::local_date{2018, toml::month_t::Apr, 1},
+                    toml::local_time{12, 30, 45})}};
+
+        const auto date = std::chrono::system_clock::to_time_t(
+                toml::find<std::chrono::system_clock::time_point>(std::move(v1), "key"));
+        std::tm t;
+        t.tm_year = 2018 - 1900;
+        t.tm_mon  = 4    - 1;
+        t.tm_mday = 1;
+        t.tm_hour = 12;
+        t.tm_min  = 30;
+        t.tm_sec  = 45;
+        t.tm_isdst = -1;
+        const auto c = std::mktime(&t);
+        BOOST_TEST(c == date);
+    }
+}
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_toml_offset_datetime, value_type, test_value_types)
+{
+    {
+        value_type v1{{"key", toml::offset_datetime(
+                    toml::local_date{2018, toml::month_t::Apr, 1},
+                    toml::local_time{12, 30, 0},
+                    toml::time_offset{9, 0})}};
+        //    2018-04-01T12:30:00+09:00
+        // == 2018-04-01T03:30:00Z
+
+        const auto date = toml::find<std::chrono::system_clock::time_point>(v1, "key");
+        const auto timet = std::chrono::system_clock::to_time_t(date);
+
+        // get time_t as gmtime (2018-04-01T03:30:00Z)
+        const auto tmp = std::gmtime(std::addressof(timet)); // XXX not threadsafe!
+        BOOST_CHECK(tmp);
+        const auto tm = *tmp;
+        BOOST_TEST(tm.tm_year + 1900 == 2018);
+        BOOST_TEST(tm.tm_mon  + 1 ==       4);
+        BOOST_TEST(tm.tm_mday ==           1);
+        BOOST_TEST(tm.tm_hour ==           3);
+        BOOST_TEST(tm.tm_min ==           30);
+        BOOST_TEST(tm.tm_sec ==            0);
+    }
+
+    {
+        value_type v1{{"key", toml::offset_datetime(
+                    toml::local_date{2018, toml::month_t::Apr, 1},
+                    toml::local_time{12, 30, 0},
+                    toml::time_offset{-8, 0})}};
+        //    2018-04-01T12:30:00-08:00
+        // == 2018-04-01T20:30:00Z
+
+        const auto date = toml::find<std::chrono::system_clock::time_point>(v1, "key");
+        const auto timet = std::chrono::system_clock::to_time_t(date);
+
+        // get time_t as gmtime (2018-04-01T03:30:00Z)
+        const auto tmp = std::gmtime(std::addressof(timet)); // XXX not threadsafe!
+        BOOST_CHECK(tmp);
+        const auto tm = *tmp;
+        BOOST_TEST(tm.tm_year + 1900 == 2018);
+        BOOST_TEST(tm.tm_mon  + 1 ==       4);
+        BOOST_TEST(tm.tm_mday ==           1);
+        BOOST_TEST(tm.tm_hour ==          20);
+        BOOST_TEST(tm.tm_min ==           30);
+        BOOST_TEST(tm.tm_sec ==            0);
+    }
+
+    {
+        value_type v1{{"key", toml::offset_datetime(
+                    toml::local_date{2018, toml::month_t::Apr, 1},
+                    toml::local_time{12, 30, 0},
+                    toml::time_offset{-8, 0})}};
+        //    2018-04-01T12:30:00-08:00
+        // == 2018-04-01T20:30:00Z
+
+        const auto date = toml::find<std::chrono::system_clock::time_point>(std::move(v1), "key");
+        const auto timet = std::chrono::system_clock::to_time_t(date);
+
+        // get time_t as gmtime (2018-04-01T03:30:00Z)
+        const auto tmp = std::gmtime(std::addressof(timet)); // XXX not threadsafe!
+        BOOST_CHECK(tmp);
+        const auto tm = *tmp;
+        BOOST_TEST(tm.tm_year + 1900 == 2018);
+        BOOST_TEST(tm.tm_mon  + 1 ==       4);
+        BOOST_TEST(tm.tm_mday ==           1);
+        BOOST_TEST(tm.tm_hour ==          20);
+        BOOST_TEST(tm.tm_min ==           30);
+        BOOST_TEST(tm.tm_sec ==            0);
+    }
+}
+

tests/test_find_or.cpp

@@ -0,0 +1,541 @@
+#define BOOST_TEST_MODULE "test_find_or"
+#ifdef UNITTEST_FRAMEWORK_LIBRARY_EXIST
+#include <boost/test/unit_test.hpp>
+#else
+#define BOOST_TEST_NO_LIB
+#include <boost/test/included/unit_test.hpp>
+#endif
+#include <toml.hpp>
+#include <map>
+#include <unordered_map>
+#include <list>
+#include <deque>
+#include <array>
+#include <tuple>
+#if __cplusplus >= 201703L
+#include <string_view>
+#endif
+
+using test_value_types = std::tuple<
+    toml::value,
+    toml::basic_value<toml::preserve_comments>,
+    toml::basic_value<toml::discard_comments,  std::map, std::deque>,
+    toml::basic_value<toml::preserve_comments, std::map, std::deque>
+>;
+
+namespace test
+{
+template<typename charT, typename traits, typename T, typename Alloc>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os, const std::vector<T, Alloc>& v)
+{
+    os << "[ ";
+    for(const auto& i : v) {os << i << ' ';}
+    os << ']';
+    return os;
+}
+template<typename charT, typename traits, typename T, typename Alloc>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os, const std::deque<T, Alloc>& v)
+{
+    os << "[ ";
+    for(const auto& i : v) {os << i << ' ';}
+    os << ']';
+    return os;
+}
+template<typename charT, typename traits, typename T, typename Alloc>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os, const std::list<T, Alloc>& v)
+{
+    os << "[ ";
+    for(const auto& i : v) {os << i << ' ';}
+    os << ']';
+    return os;
+}
+template<typename charT, typename traits,
+         typename Key, typename Value, typename Comp, typename Alloc>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os,
+           const std::map<Key, Value, Comp, Alloc>& v)
+{
+    os << "[ ";
+    for(const auto& i : v) {os << '{' << i.first << ", " << i.second << "} ";}
+    os << ']';
+    return os;
+}
+template<typename charT, typename traits,
+         typename Key, typename Value, typename Hash, typename Eq, typename Alloc>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os,
+           const std::unordered_map<Key, Value, Hash, Eq, Alloc>& v)
+{
+    os << "[ ";
+    for(const auto& i : v) {os << '{' << i.first << ", " << i.second << "} ";}
+    os << ']';
+    return os;
+}
+} // test
+
+#define TOML11_TEST_FIND_OR_EXACT(toml_type, init_expr, opt_expr)\
+    {                                                           \
+        using namespace test;                                   \
+        const toml::toml_type init init_expr ;                  \
+        const toml::toml_type opt  opt_expr ;                   \
+        const value_type v{{"key", init}};                      \
+        BOOST_TEST(init != opt);                                \
+        BOOST_TEST(init == toml::find_or(v, "key", opt));       \
+    }                                                           \
+    /**/
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_or_exact, value_type, test_value_types)
+{
+    TOML11_TEST_FIND_OR_EXACT(boolean,         ( true), (false))
+    TOML11_TEST_FIND_OR_EXACT(integer,         (   42), (   54))
+    TOML11_TEST_FIND_OR_EXACT(floating,        ( 3.14), ( 2.71))
+    TOML11_TEST_FIND_OR_EXACT(string,          ("foo"), ("bar"))
+    TOML11_TEST_FIND_OR_EXACT(local_time,      (12, 30, 45), (6, 0, 30))
+    TOML11_TEST_FIND_OR_EXACT(local_date,      (2019, toml::month_t::Apr, 1),
+                                              (1999, toml::month_t::Jan, 2))
+    TOML11_TEST_FIND_OR_EXACT(local_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30))
+            )
+    TOML11_TEST_FIND_OR_EXACT(offset_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45), toml::time_offset( 9, 0)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30), toml::time_offset(-3, 0))
+            )
+    {
+        const typename value_type::array_type init{1,2,3,4,5};
+        const typename value_type::array_type opt {6,7,8,9,10};
+        const value_type v{{"key", init}};
+        BOOST_TEST(init != opt);
+        BOOST_TEST(init == toml::find_or(v, "key", opt));
+    }
+    {
+        const typename value_type::table_type init{{"key1", 42}, {"key2", "foo"}};
+        const typename value_type::table_type opt {{"key1", 54}, {"key2", "bar"}};
+        const value_type v{{"key", init}};
+        BOOST_TEST(init != opt);
+        BOOST_TEST(init == toml::find_or(v, "key", opt));
+    }
+}
+#undef TOML11_TEST_FIND_OR_EXACT
+
+#define TOML11_TEST_FIND_OR_MOVE(toml_type, init_expr, opt_expr)   \
+    {                                                              \
+        using namespace test;                                      \
+        const toml::toml_type init init_expr ;                     \
+        toml::toml_type opt  opt_expr ;                            \
+        value_type v{{"key", init}};                               \
+        BOOST_TEST(init != opt);                                   \
+        const auto moved = toml::find_or(std::move(v), "key", std::move(opt));\
+        BOOST_TEST(init == moved);                                 \
+    }                                                              \
+    /**/
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_or_move, value_type, test_value_types)
+{
+    TOML11_TEST_FIND_OR_MOVE(boolean,         ( true), (false))
+    TOML11_TEST_FIND_OR_MOVE(integer,         (   42), (   54))
+    TOML11_TEST_FIND_OR_MOVE(floating,        ( 3.14), ( 2.71))
+    TOML11_TEST_FIND_OR_MOVE(string,          ("foo"), ("bar"))
+    TOML11_TEST_FIND_OR_MOVE(local_time,      (12, 30, 45), (6, 0, 30))
+    TOML11_TEST_FIND_OR_MOVE(local_date,      (2019, toml::month_t::Apr, 1),
+                                              (1999, toml::month_t::Jan, 2))
+    TOML11_TEST_FIND_OR_MOVE(local_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30))
+            )
+    TOML11_TEST_FIND_OR_MOVE(offset_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45), toml::time_offset( 9, 0)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30), toml::time_offset(-3, 0))
+            )
+    {
+        typename value_type::array_type init{1,2,3,4,5};
+        typename value_type::array_type opt {6,7,8,9,10};
+        value_type v{{"key", init}};
+        BOOST_TEST(init != opt);
+        const auto moved = toml::find_or(std::move(v), "key", std::move(opt));
+        BOOST_TEST(init == moved);
+    }
+    {
+        typename value_type::table_type init{{"key1", 42}, {"key2", "foo"}};
+        typename value_type::table_type opt {{"key1", 54}, {"key2", "bar"}};
+        value_type v{{"key", init}};
+        BOOST_TEST(init != opt);
+        const auto moved = toml::find_or(std::move(v), "key", std::move(opt));
+        BOOST_TEST(init == moved);
+    }
+}
+#undef TOML11_TEST_FIND_OR_MOVE
+
+
+#define TOML11_TEST_FIND_OR_MODIFY(toml_type, init_expr, opt_expr)\
+    {                                                             \
+        using namespace test;                                     \
+        const toml::toml_type init init_expr ;                    \
+        toml::toml_type       opt1 opt_expr ;                     \
+        toml::toml_type       opt2 opt_expr ;                     \
+        value_type v{{"key", init}};                              \
+        BOOST_TEST(init != opt1);                                 \
+        toml::find_or(v, "key", opt2) = opt1;                     \
+        BOOST_TEST(opt1 == toml::find<toml::toml_type>(v, "key"));\
+    }                                                             \
+    /**/
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_or_modify, value_type, test_value_types)
+{
+    TOML11_TEST_FIND_OR_MODIFY(boolean,         ( true), (false))
+    TOML11_TEST_FIND_OR_MODIFY(integer,         (   42), (   54))
+    TOML11_TEST_FIND_OR_MODIFY(floating,        ( 3.14), ( 2.71))
+    TOML11_TEST_FIND_OR_MODIFY(string,          ("foo"), ("bar"))
+    TOML11_TEST_FIND_OR_MODIFY(local_time,      (12, 30, 45), (6, 0, 30))
+    TOML11_TEST_FIND_OR_MODIFY(local_date,      (2019, toml::month_t::Apr, 1),
+                                              (1999, toml::month_t::Jan, 2))
+    TOML11_TEST_FIND_OR_MODIFY(local_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30))
+            )
+    TOML11_TEST_FIND_OR_MODIFY(offset_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45), toml::time_offset( 9, 0)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30), toml::time_offset(-3, 0))
+            )
+    {
+        typename value_type::array_type init{1,2,3,4,5};
+        typename value_type::array_type opt1{6,7,8,9,10};
+        typename value_type::array_type opt2{6,7,8,9,10};
+        BOOST_TEST(init != opt1);
+        value_type v{{"key", init}};
+        toml::find_or(v, "key", opt2) = opt1;
+        BOOST_TEST(opt1 == toml::find<typename value_type::array_type>(v, "key"));
+    }
+    {
+        typename value_type::table_type init{{"key1", 42}, {"key2", "foo"}};
+        typename value_type::table_type opt1{{"key1", 54}, {"key2", "bar"}};
+        typename value_type::table_type opt2{{"key1", 54}, {"key2", "bar"}};
+        value_type v{{"key", init}};
+        BOOST_TEST(init != opt1);
+        toml::find_or(v, "key", opt2) = opt1;
+        BOOST_TEST(opt1 == toml::find<typename value_type::table_type>(v, "key"));
+    }
+}
+#undef TOML11_TEST_FIND_OR_MODIFY
+
+#define TOML11_TEST_FIND_OR_FALLBACK(init_type, opt_type)         \
+    {                                                             \
+        using namespace test;                                     \
+        value_type v(init_type);                                  \
+        BOOST_TEST(opt_type == toml::find_or(v, "key", opt_type));\
+    }                                                             \
+    /**/
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_find_or_fallback, value_type, test_value_types)
+{
+    const toml::boolean         boolean        (true);
+    const toml::integer         integer        (42);
+    const toml::floating        floating       (3.14);
+    const toml::string          string         ("foo");
+    const toml::local_time      local_time     (12, 30, 45);
+    const toml::local_date      local_date     (2019, toml::month_t::Apr, 1);
+    const toml::local_datetime  local_datetime (
+            toml::local_date(2019, toml::month_t::Apr, 1),
+            toml::local_time(12, 30, 45));
+    const toml::offset_datetime offset_datetime(
+            toml::local_date(2019, toml::month_t::Apr, 1),
+            toml::local_time(12, 30, 45), toml::time_offset( 9, 0));
+
+    using array_type = typename value_type::array_type;
+    using table_type = typename value_type::table_type;
+    const array_type array{1, 2, 3, 4, 5};
+    const table_type table{{"key1", 42}, {"key2", "foo"}};
+
+    TOML11_TEST_FIND_OR_FALLBACK(boolean, integer        );
+    TOML11_TEST_FIND_OR_FALLBACK(boolean, floating       );
+    TOML11_TEST_FIND_OR_FALLBACK(boolean, string         );
+    TOML11_TEST_FIND_OR_FALLBACK(boolean, local_time     );
+    TOML11_TEST_FIND_OR_FALLBACK(boolean, local_date     );
+    TOML11_TEST_FIND_OR_FALLBACK(boolean, local_datetime );
+    TOML11_TEST_FIND_OR_FALLBACK(boolean, offset_datetime);
+    TOML11_TEST_FIND_OR_FALLBACK(boolean, array          );
+    TOML11_TEST_FIND_OR_FALLBACK(boolean, table          );
+
+    TOML11_TEST_FIND_OR_FALLBACK(integer, boolean        );
+    TOML11_TEST_FIND_OR_FALLBACK(integer, floating       );
+    TOML11_TEST_FIND_OR_FALLBACK(integer, string         );
+    TOML11_TEST_FIND_OR_FALLBACK(integer, local_time     );
+    TOML11_TEST_FIND_OR_FALLBACK(integer, local_date     );
+    TOML11_TEST_FIND_OR_FALLBACK(integer, local_datetime );
+    TOML11_TEST_FIND_OR_FALLBACK(integer, offset_datetime);
+    TOML11_TEST_FIND_OR_FALLBACK(integer, array          );
+    TOML11_TEST_FIND_OR_FALLBACK(integer, table          );
+
+    TOML11_TEST_FIND_OR_FALLBACK(floating, boolean        );
+    TOML11_TEST_FIND_OR_FALLBACK(floating, integer        );
+    TOML11_TEST_FIND_OR_FALLBACK(floating, string         );
+    TOML11_TEST_FIND_OR_FALLBACK(floating, local_time     );
+    TOML11_TEST_FIND_OR_FALLBACK(floating, local_date     );
+    TOML11_TEST_FIND_OR_FALLBACK(floating, local_datetime );
+    TOML11_TEST_FIND_OR_FALLBACK(floating, offset_datetime);
+    TOML11_TEST_FIND_OR_FALLBACK(floating, array          );
+    TOML11_TEST_FIND_OR_FALLBACK(floating, table          );
+
+    TOML11_TEST_FIND_OR_FALLBACK(string, boolean        );
+    TOML11_TEST_FIND_OR_FALLBACK(string, integer        );
+    TOML11_TEST_FIND_OR_FALLBACK(string, floating       );
+    TOML11_TEST_FIND_OR_FALLBACK(string, local_time     );
+    TOML11_TEST_FIND_OR_FALLBACK(string, local_date     );
+    TOML11_TEST_FIND_OR_FALLBACK(string, local_datetime );
+    TOML11_TEST_FIND_OR_FALLBACK(string, offset_datetime);
+    TOML11_TEST_FIND_OR_FALLBACK(string, array          );
+    TOML11_TEST_FIND_OR_FALLBACK(string, table          );
+
+    TOML11_TEST_FIND_OR_FALLBACK(local_time, boolean        );
+    TOML11_TEST_FIND_OR_FALLBACK(local_time, integer        );
+    TOML11_TEST_FIND_OR_FALLBACK(local_time, floating       );
+    TOML11_TEST_FIND_OR_FALLBACK(local_time, string         );
+    TOML11_TEST_FIND_OR_FALLBACK(local_time, local_date     );
+    TOML11_TEST_FIND_OR_FALLBACK(local_time, local_datetime );
+    TOML11_TEST_FIND_OR_FALLBACK(local_time, offset_datetime);
+    TOML11_TEST_FIND_OR_FALLBACK(local_time, array          );
+    TOML11_TEST_FIND_OR_FALLBACK(local_time, table          );
+
+    TOML11_TEST_FIND_OR_FALLBACK(local_date, boolean        );
+    TOML11_TEST_FIND_OR_FALLBACK(local_date, integer        );
+    TOML11_TEST_FIND_OR_FALLBACK(local_date, floating       );
+    TOML11_TEST_FIND_OR_FALLBACK(local_date, string         );
+    TOML11_TEST_FIND_OR_FALLBACK(local_date, local_time     );
+    TOML11_TEST_FIND_OR_FALLBACK(local_date, local_datetime );
+    TOML11_TEST_FIND_OR_FALLBACK(local_date, offset_datetime);
+    TOML11_TEST_FIND_OR_FALLBACK(local_date, array          );
+    TOML11_TEST_FIND_OR_FALLBACK(local_date, table          );
+
+    TOML11_TEST_FIND_OR_FALLBACK(local_datetime, boolean        );
+    TOML11_TEST_FIND_OR_FALLBACK(local_datetime, integer        );
+    TOML11_TEST_FIND_OR_FALLBACK(local_datetime, floating       );
+    TOML11_TEST_FIND_OR_FALLBACK(local_datetime, string         );
+    TOML11_TEST_FIND_OR_FALLBACK(local_datetime, local_time     );
+    TOML11_TEST_FIND_OR_FALLBACK(local_datetime, local_date     );
+    TOML11_TEST_FIND_OR_FALLBACK(local_datetime, offset_datetime);
+    TOML11_TEST_FIND_OR_FALLBACK(local_datetime, array          );
+    TOML11_TEST_FIND_OR_FALLBACK(local_datetime, table          );
+
+    TOML11_TEST_FIND_OR_FALLBACK(offset_datetime, boolean        );
+    TOML11_TEST_FIND_OR_FALLBACK(offset_datetime, integer        );
+    TOML11_TEST_FIND_OR_FALLBACK(offset_datetime, floating       );
+    TOML11_TEST_FIND_OR_FALLBACK(offset_datetime, string         );
+    TOML11_TEST_FIND_OR_FALLBACK(offset_datetime, local_time     );
+    TOML11_TEST_FIND_OR_FALLBACK(offset_datetime, local_date     );
+    TOML11_TEST_FIND_OR_FALLBACK(offset_datetime, local_datetime );
+    TOML11_TEST_FIND_OR_FALLBACK(offset_datetime, array          );
+    TOML11_TEST_FIND_OR_FALLBACK(offset_datetime, table          );
+
+    TOML11_TEST_FIND_OR_FALLBACK(array, boolean        );
+    TOML11_TEST_FIND_OR_FALLBACK(array, integer        );
+    TOML11_TEST_FIND_OR_FALLBACK(array, floating       );
+    TOML11_TEST_FIND_OR_FALLBACK(array, string         );
+    TOML11_TEST_FIND_OR_FALLBACK(array, local_time     );
+    TOML11_TEST_FIND_OR_FALLBACK(array, local_date     );
+    TOML11_TEST_FIND_OR_FALLBACK(array, local_datetime );
+    TOML11_TEST_FIND_OR_FALLBACK(array, offset_datetime);
+    TOML11_TEST_FIND_OR_FALLBACK(array, table          );
+
+    TOML11_TEST_FIND_OR_FALLBACK(table, boolean        );
+    TOML11_TEST_FIND_OR_FALLBACK(table, integer        );
+    TOML11_TEST_FIND_OR_FALLBACK(table, floating       );
+    TOML11_TEST_FIND_OR_FALLBACK(table, string         );
+    TOML11_TEST_FIND_OR_FALLBACK(table, local_time     );
+    TOML11_TEST_FIND_OR_FALLBACK(table, local_date     );
+    TOML11_TEST_FIND_OR_FALLBACK(table, local_datetime );
+    TOML11_TEST_FIND_OR_FALLBACK(table, offset_datetime);
+    TOML11_TEST_FIND_OR_FALLBACK(table, array          );
+}
+#undef TOML11_TEST_FIND_OR_FALLBACK
+
+BOOST_AUTO_TEST_CASE(test_find_or_integer)
+{
+    {
+        toml::value v{{"num", 42}};
+        BOOST_TEST(42u == toml::find_or(v, "num", 0u));
+        BOOST_TEST(0u ==  toml::find_or(v, "foo", 0u));
+    }
+    {
+        toml::value v{{"num", 42}};
+        const auto moved = toml::find_or(std::move(v), "num", 0u);
+        BOOST_TEST(42u == moved);
+    }
+    {
+        toml::value v{{"num", 42}};
+        const auto moved = toml::find_or(std::move(v), "foo", 0u);
+        BOOST_TEST(0u ==  moved);
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_find_or_floating)
+{
+    {
+        toml::value v1{{"key", 42}};
+        toml::value v2{{"key", 3.14}};
+        BOOST_TEST(2.71f == toml::find_or(v1, "key", 2.71f));
+        const double ref(3.14);
+        BOOST_TEST(static_cast<float>(ref) == toml::find_or(v2, "key", 2.71f));
+    }
+    {
+        toml::value v1{{"key", 42}};
+        toml::value v2{{"key", 3.14}};
+        const auto moved1 = toml::find_or(std::move(v1), "key", 2.71f);
+        const auto moved2 = toml::find_or(std::move(v2), "key", 2.71f);
+        BOOST_TEST(2.71f == moved1);
+        const double ref(3.14);
+        BOOST_TEST(static_cast<float>(ref) == moved2);
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_find_or_string)
+{
+    {
+        toml::value v1 = toml::table{{"key", "foobar"}};
+        toml::value v2 = toml::table{{"key", 42}};
+
+        std::string       s1("bazqux");
+        const std::string s2("bazqux");
+
+        BOOST_TEST("foobar" == toml::find_or(v1, "key", s1));
+        BOOST_TEST("bazqux" == toml::find_or(v2, "key", s1));
+
+        std::string& v1r = toml::find_or(v1, "key", s1);
+        std::string& s1r = toml::find_or(v2, "key", s1);
+
+        BOOST_TEST("foobar" == v1r);
+        BOOST_TEST("bazqux" == s1r);
+
+        BOOST_TEST("foobar" == toml::find_or(v1, "key", s2));
+        BOOST_TEST("bazqux" == toml::find_or(v2, "key", s2));
+
+        BOOST_TEST("foobar" == toml::find_or(std::move(v1), "key", std::move(s1)));
+        s1 = "bazqux"; // restoring moved value
+        BOOST_TEST("bazqux" == toml::find_or(std::move(v2), "key", std::move(s1)));
+    }
+    {
+        toml::value v1 = toml::table{{"key", "foobar"}};
+        toml::value v2 = toml::table{{"key", 42}};
+
+        std::string s1("bazqux");
+
+        const auto moved1 = toml::find_or(std::move(v1), "key", s1);
+        const auto moved2 = toml::find_or(std::move(v2), "key", s1);
+
+        BOOST_TEST("foobar" == moved1);
+        BOOST_TEST("bazqux" == moved2);
+    }
+    {
+        toml::value v1 = toml::table{{"key", "foobar"}};
+        toml::value v2 = toml::table{{"key", 42}};
+
+        std::string s1("bazqux");
+        std::string s2("bazqux");
+
+        const auto moved1 = toml::find_or(std::move(v1), "key", std::move(s1));
+        const auto moved2 = toml::find_or(std::move(v2), "key", std::move(s2));
+
+        BOOST_TEST("foobar" == moved1);
+        BOOST_TEST("bazqux" == moved2);
+    }
+
+    // string literal
+    {
+        toml::value v1 = toml::table{{"key", "foobar"}};
+        toml::value v2 = toml::table{{"key",42}};
+
+        BOOST_TEST("foobar" == toml::find_or(v1, "key", "bazqux"));
+        BOOST_TEST("bazqux" == toml::find_or(v2, "key", "bazqux"));
+
+        const char* lit = "bazqux";
+        BOOST_TEST("foobar" == toml::find_or(v1, "key", lit));
+        BOOST_TEST("bazqux" == toml::find_or(v2, "key", lit));
+    }
+    {
+        toml::value v1 = toml::table{{"key", "foobar"}};
+        toml::value v2 = toml::table{{"key",42}};
+
+        const auto moved1 = toml::find_or(std::move(v1), "key", "bazqux");
+        const auto moved2 = toml::find_or(std::move(v2), "key", "bazqux");
+
+        BOOST_TEST("foobar" == moved1);
+        BOOST_TEST("bazqux" == moved2);
+    }
+    {
+        toml::value v1 = toml::table{{"key", "foobar"}};
+        toml::value v2 = toml::table{{"key",42}};
+
+        const char* lit = "bazqux";
+        const auto moved1 = toml::find_or(std::move(v1), "key", lit);
+        const auto moved2 = toml::find_or(std::move(v2), "key", lit);
+
+        BOOST_TEST("foobar" == moved1);
+        BOOST_TEST("bazqux" == moved2);
+    }
+
+}
+
+BOOST_AUTO_TEST_CASE(test_find_or_map)
+{
+    using map_type = std::map<std::string, std::string>;
+    {
+        const toml::value v1{
+            {"key", {{"key", "value"}}}
+        };
+
+        const auto key  = toml::find_or(v1, "key",  map_type{});
+        const auto key2 = toml::find_or(v1, "key2", map_type{});
+
+        BOOST_TEST(!key.empty());
+        BOOST_TEST(key2.empty());
+
+        BOOST_TEST(key.size()    == 1u);
+        BOOST_TEST(key.at("key") == "value");
+    }
+    {
+        toml::value v1{
+            {"key", {{"key", "value"}}}
+        };
+
+        const auto key  = toml::find_or<map_type>(v1, "key",  map_type{});
+        const auto key2 = toml::find_or<map_type>(v1, "key2", map_type{});
+
+        BOOST_TEST(!key.empty());
+        BOOST_TEST(key2.empty());
+
+        BOOST_TEST(key.size()    == 1u);
+        BOOST_TEST(key.at("key") == "value");
+    }
+
+    {
+        toml::value v1{
+            {"key", {{"key", "value"}}}
+        };
+        toml::value v2(v1);
+
+        const auto key  = toml::find_or(std::move(v1), "key",  map_type{});
+        const auto key2 = toml::find_or(std::move(v2), "key2", map_type{});
+
+        BOOST_TEST(!key.empty());
+        BOOST_TEST(key2.empty());
+
+        BOOST_TEST(key.size()    == 1u);
+        BOOST_TEST(key.at("key") == "value");
+    }
+    {
+        toml::value v1{
+            {"key", {{"key", "value"}}}
+        };
+        toml::value v2(v1);
+
+        const auto key  = toml::find_or<map_type>(std::move(v1), "key",  map_type{});
+        const auto key2 = toml::find_or<map_type>(std::move(v2), "key2", map_type{});
+
+        BOOST_TEST(!key.empty());
+        BOOST_TEST(key2.empty());
+
+        BOOST_TEST(key.size()    == 1u);
+        BOOST_TEST(key.at("key") == "value");
+    }
+}

tests/test_format_error.cpp

@@ -1,4 +1,4 @@
-#define BOOST_TEST_MODULE "test_value"
+#define BOOST_TEST_MODULE "test_format_error"
 #ifdef UNITTEST_FRAMEWORK_LIBRARY_EXIST
 #include <boost/test/unit_test.hpp>
 #else
@@ -6,6 +6,7 @@
 #include <boost/test/included/unit_test.hpp>
 #endif
 #include <toml.hpp>
+#include <iostream>
 
 // to check it successfully compiles. it does not check the formatted string.
 

tests/test_from_toml.cpp

@@ -1,63 +0,0 @@
-#define BOOST_TEST_MODULE "test_from_toml"
-#ifdef UNITTEST_FRAMEWORK_LIBRARY_EXIST
-#include <boost/test/unit_test.hpp>
-#else
-#define BOOST_TEST_NO_LIB
-#include <boost/test/included/unit_test.hpp>
-#endif
-#include <toml.hpp>
-#include <map>
-#include <unordered_map>
-#include <list>
-#include <deque>
-#include <array>
-
-BOOST_AUTO_TEST_CASE(test_from_toml)
-{
-    toml::boolean    b = false;
-    toml::integer    i = 0;
-    toml::floating   f = 0.;
-    toml::string     s;
-    toml::local_date dt;
-    toml::array      a;
-    toml::table      t;
-    {
-        toml::value v(true);
-        toml::from_toml(std::tie(b, i, f, s, dt, a, t), v);
-        BOOST_CHECK_EQUAL(b, true);
-    }
-    {
-        toml::value v(42);
-        toml::from_toml(std::tie(b, i, f, s, dt, a, t), v);
-        BOOST_CHECK_EQUAL(i, 42);
-    }
-    {
-        toml::value v(3.14);
-        toml::from_toml(std::tie(b, i, f, s, dt, a, t), v);
-        BOOST_CHECK_EQUAL(f, 3.14);
-    }
-    {
-        toml::value v("foo");
-
-        toml::from_toml(std::tie(b, i, f, s, dt, a, t), v);
-        BOOST_CHECK_EQUAL(s, "foo");
-    }
-    {
-        toml::value v(toml::local_date(2018, toml::month_t::Apr, 22));
-        toml::from_toml(std::tie(b, i, f, s, dt, a, t), v);
-        BOOST_CHECK(dt == toml::local_date(2018, toml::month_t::Apr, 22));
-    }
-    {
-        toml::array ref{toml::value(42), toml::value(54)};
-        toml::value v(ref);
-        toml::from_toml(std::tie(b, i, f, s, dt, a, t), v);
-        BOOST_CHECK(ref == a);
-    }
-    {
-        toml::table ref{{"key1", 42}, {"key2", 3.14}};
-        toml::value v(ref);
-        toml::from_toml(std::tie(b, i, f, s, dt, a, t), v);
-        BOOST_CHECK(ref == t);
-    }
-}
-

tests/test_get.cpp

@@ -5,294 +5,414 @@
 #define BOOST_TEST_NO_LIB
 #include <boost/test/included/unit_test.hpp>
 #endif
-#include <toml/value.hpp>
-#include <toml/get.hpp>
+#include <toml.hpp>
 #include <map>
 #include <unordered_map>
 #include <list>
 #include <deque>
 #include <array>
+#include <tuple>
 #if __cplusplus >= 201703L
 #include <string_view>
 #endif
 
+using test_value_types = std::tuple<
+    toml::value,
+    toml::basic_value<toml::preserve_comments>,
+    toml::basic_value<toml::discard_comments,  std::map, std::deque>,
+    toml::basic_value<toml::preserve_comments, std::map, std::deque>
+>;
 
-BOOST_AUTO_TEST_CASE(test_get_exact)
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_exact, value_type, test_value_types)
 {
     {
-        toml::value v(true);
-        BOOST_CHECK_EQUAL(true, toml::get<toml::boolean>(v));
+        value_type v(true);
+        BOOST_TEST(true == toml::get<toml::boolean>(v));
 
         toml::get<toml::boolean>(v) = false;
-        BOOST_CHECK_EQUAL(false, toml::get<toml::boolean>(v));
+        BOOST_TEST(false == toml::get<toml::boolean>(v));
+
+        toml::boolean x = toml::get<toml::boolean>(std::move(v));
+        BOOST_TEST(false == x);
     }
     {
-        toml::value v(42);
-        BOOST_CHECK_EQUAL(toml::integer(42), toml::get<toml::integer>(v));
+        value_type v(42);
+        BOOST_TEST(toml::integer(42) == toml::get<toml::integer>(v));
 
         toml::get<toml::integer>(v) = 54;
-        BOOST_CHECK_EQUAL(toml::integer(54), toml::get<toml::integer>(v));
+        BOOST_TEST(toml::integer(54) == toml::get<toml::integer>(v));
+
+        toml::integer x = toml::get<toml::integer>(std::move(v));
+        BOOST_TEST(toml::integer(54) == x);
     }
     {
-        toml::value v(3.14);
-        BOOST_CHECK_EQUAL(toml::floating(3.14), toml::get<toml::floating>(v));
+        value_type v(3.14);
+        BOOST_TEST(toml::floating(3.14) == toml::get<toml::floating>(v));
 
         toml::get<toml::floating>(v) = 2.71;
-        BOOST_CHECK_EQUAL(toml::floating(2.71), toml::get<toml::floating>(v));
+        BOOST_TEST(toml::floating(2.71) == toml::get<toml::floating>(v));
+
+        toml::floating x = toml::get<toml::floating>(std::move(v));
+        BOOST_TEST(toml::floating(2.71) == x);
     }
     {
-        toml::value v("foo");
-        BOOST_CHECK_EQUAL(toml::string("foo", toml::string_t::basic),
+        value_type v("foo");
+        BOOST_TEST(toml::string("foo", toml::string_t::basic) ==
                           toml::get<toml::string>(v));
 
         toml::get<toml::string>(v).str += "bar";
-        BOOST_CHECK_EQUAL(toml::string("foobar", toml::string_t::basic),
+        BOOST_TEST(toml::string("foobar", toml::string_t::basic) ==
                           toml::get<toml::string>(v));
+
+        toml::string x = toml::get<toml::string>(std::move(v));
+        BOOST_TEST(toml::string("foobar") == x);
     }
     {
-        toml::value v("foo", toml::string_t::literal);
-        BOOST_CHECK_EQUAL(toml::string("foo", toml::string_t::literal),
+        value_type v("foo", toml::string_t::literal);
+        BOOST_TEST(toml::string("foo", toml::string_t::literal) ==
                           toml::get<toml::string>(v));
 
         toml::get<toml::string>(v).str += "bar";
-        BOOST_CHECK_EQUAL(toml::string("foobar", toml::string_t::literal),
+        BOOST_TEST(toml::string("foobar", toml::string_t::literal) ==
                           toml::get<toml::string>(v));
+
+        toml::string x = toml::get<toml::string>(std::move(v));
+        BOOST_TEST(toml::string("foobar", toml::string_t::literal) == x);
     }
     {
         toml::local_date d(2018, toml::month_t::Apr, 22);
-        toml::value v(d);
-        BOOST_CHECK(d == toml::get<toml::local_date>(v));
+        value_type v(d);
+        BOOST_TEST(d == toml::get<toml::local_date>(v));
 
         toml::get<toml::local_date>(v).year = 2017;
         d.year = 2017;
-        BOOST_CHECK(d == toml::get<toml::local_date>(v));
+        BOOST_TEST(d == toml::get<toml::local_date>(v));
+
+        toml::local_date x = toml::get<toml::local_date>(std::move(v));
+        BOOST_TEST(d == x);
     }
     {
         toml::local_time t(12, 30, 45);
-        toml::value v(t);
-        BOOST_CHECK(t == toml::get<toml::local_time>(v));
+        value_type v(t);
+        BOOST_TEST(t == toml::get<toml::local_time>(v));
 
         toml::get<toml::local_time>(v).hour = 9;
         t.hour = 9;
-        BOOST_CHECK(t == toml::get<toml::local_time>(v));
+        BOOST_TEST(t == toml::get<toml::local_time>(v));
+
+        toml::local_time x = toml::get<toml::local_time>(std::move(v));
+        BOOST_TEST(t == x);
     }
     {
         toml::local_datetime dt(toml::local_date(2018, toml::month_t::Apr, 22),
                                 toml::local_time(12, 30, 45));
-        toml::value v(dt);
-        BOOST_CHECK(dt == toml::get<toml::local_datetime>(v));
+        value_type v(dt);
+        BOOST_TEST(dt == toml::get<toml::local_datetime>(v));
 
         toml::get<toml::local_datetime>(v).date.year = 2017;
         dt.date.year = 2017;
-        BOOST_CHECK(dt == toml::get<toml::local_datetime>(v));
+        BOOST_TEST(dt == toml::get<toml::local_datetime>(v));
+
+        toml::local_datetime x = toml::get<toml::local_datetime>(std::move(v));
+        BOOST_TEST(dt == x);
     }
     {
         toml::offset_datetime dt(toml::local_datetime(
                     toml::local_date(2018, toml::month_t::Apr, 22),
                     toml::local_time(12, 30, 45)), toml::time_offset(9, 0));
-        toml::value v(dt);
-        BOOST_CHECK(dt == toml::get<toml::offset_datetime>(v));
+        value_type v(dt);
+        BOOST_TEST(dt == toml::get<toml::offset_datetime>(v));
 
         toml::get<toml::offset_datetime>(v).date.year = 2017;
         dt.date.year = 2017;
-        BOOST_CHECK(dt == toml::get<toml::offset_datetime>(v));
+        BOOST_TEST(dt == toml::get<toml::offset_datetime>(v));
+
+        toml::offset_datetime x = toml::get<toml::offset_datetime>(std::move(v));
+        BOOST_TEST(dt == x);
     }
     {
-        toml::array vec;
-        vec.push_back(toml::value(42));
-        vec.push_back(toml::value(54));
-        toml::value v(vec);
-        BOOST_CHECK(vec == toml::get<toml::array>(v));
+        using array_type = typename value_type::array_type;
+        array_type vec;
+        vec.push_back(value_type(42));
+        vec.push_back(value_type(54));
+        value_type v(vec);
+        BOOST_TEST(vec == toml::get<array_type>(v));
 
-        toml::get<toml::array>(v).push_back(toml::value(123));
-        vec.push_back(toml::value(123));
-        BOOST_CHECK(vec == toml::get<toml::array>(v));
+        toml::get<array_type>(v).push_back(value_type(123));
+        vec.push_back(value_type(123));
+        BOOST_TEST(vec == toml::get<array_type>(v));
+
+        array_type x = toml::get<array_type>(std::move(v));
+        BOOST_TEST(vec == x);
     }
     {
-        toml::table tab;
-        tab["key1"] = toml::value(42);
-        tab["key2"] = toml::value(3.14);
-        toml::value v(tab);
-        BOOST_CHECK(tab == toml::get<toml::table>(v));
+        using table_type = typename value_type::table_type;
+        table_type tab;
+        tab["key1"] = value_type(42);
+        tab["key2"] = value_type(3.14);
+        value_type v(tab);
+        BOOST_TEST(tab == toml::get<table_type>(v));
 
-        toml::get<toml::table>(v)["key3"] = toml::value(123);
-        tab["key3"] = toml::value(123);
-        BOOST_CHECK(tab == toml::get<toml::table>(v));
+        toml::get<table_type>(v)["key3"] = value_type(123);
+        tab["key3"] = value_type(123);
+        BOOST_TEST(tab == toml::get<table_type>(v));
+
+        table_type x = toml::get<table_type>(std::move(v));
+        BOOST_TEST(tab == x);
     }
     {
-        toml::value v1(42);
-        BOOST_CHECK(v1 == toml::get<toml::value>(v1));
+        value_type v1(42);
+        BOOST_TEST(v1 == toml::get<value_type>(v1));
 
-        toml::value v2(54);
-        toml::get<toml::value>(v1) = v2;
-        BOOST_CHECK(v2 == toml::get<toml::value>(v1));
+        value_type v2(54);
+        toml::get<value_type>(v1) = v2;
+        BOOST_TEST(v2 == toml::get<value_type>(v1));
+
+        value_type x = toml::get<value_type>(std::move(v1));
+        BOOST_TEST(v2 == x);
     }
 }
 
-BOOST_AUTO_TEST_CASE(test_get_integer_type)
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_integer_type, value_type, test_value_types)
 {
     {
-        toml::value v(42);
-        BOOST_CHECK_EQUAL(int(42),           toml::get<int          >(v));
-        BOOST_CHECK_EQUAL(short(42),         toml::get<short        >(v));
-        BOOST_CHECK_EQUAL(char(42),          toml::get<char         >(v));
-        BOOST_CHECK_EQUAL(unsigned(42),      toml::get<unsigned     >(v));
-        BOOST_CHECK_EQUAL(long(42),          toml::get<long         >(v));
-        BOOST_CHECK_EQUAL(std::int64_t(42),  toml::get<std::int64_t >(v));
-        BOOST_CHECK_EQUAL(std::uint64_t(42), toml::get<std::uint64_t>(v));
-        BOOST_CHECK_EQUAL(std::int16_t(42),  toml::get<std::int16_t >(v));
-        BOOST_CHECK_EQUAL(std::uint16_t(42), toml::get<std::uint16_t>(v));
+        value_type v(42);
+        BOOST_TEST(int(42) ==           toml::get<int          >(v));
+        BOOST_TEST(short(42) ==         toml::get<short        >(v));
+        BOOST_TEST(char(42) ==          toml::get<char         >(v));
+        BOOST_TEST(unsigned(42) ==      toml::get<unsigned     >(v));
+        BOOST_TEST(long(42) ==          toml::get<long         >(v));
+        BOOST_TEST(std::int64_t(42) ==  toml::get<std::int64_t >(v));
+        BOOST_TEST(std::uint64_t(42) == toml::get<std::uint64_t>(v));
+        BOOST_TEST(std::int16_t(42) ==  toml::get<std::int16_t >(v));
+        BOOST_TEST(std::uint16_t(42) == toml::get<std::uint16_t>(v));
+
+        BOOST_TEST(std::uint16_t(42) == toml::get<std::uint16_t>(std::move(v)));
     }
 }
 
-BOOST_AUTO_TEST_CASE(test_get_floating_type)
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_floating_type, value_type, test_value_types)
 {
     {
-        toml::value v(3.14);
-        BOOST_CHECK_EQUAL(static_cast<float      >(3.14), toml::get<float      >(v));
-        BOOST_CHECK_EQUAL(static_cast<double     >(3.14), toml::get<double     >(v));
-        BOOST_CHECK_EQUAL(static_cast<long double>(3.14), toml::get<long double>(v));
+        value_type v(3.14);
+        const double ref(3.14);
+        BOOST_TEST(static_cast<float      >(ref) == toml::get<float      >(v));
+        BOOST_TEST(                         ref  == toml::get<double     >(v));
+        BOOST_TEST(static_cast<long double>(ref) == toml::get<long double>(v));
+        BOOST_TEST(static_cast<float      >(ref) == toml::get<float>(std::move(v)));
     }
 }
 
-BOOST_AUTO_TEST_CASE(test_get_string_type)
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_string_type, value_type, test_value_types)
 {
     {
-        toml::value v("foo", toml::string_t::basic);
-        BOOST_CHECK_EQUAL("foo", toml::get<std::string>(v));
+        value_type v("foo", toml::string_t::basic);
+        BOOST_TEST("foo" == toml::get<std::string>(v));
         toml::get<std::string>(v) += "bar";
-        BOOST_CHECK_EQUAL("foobar", toml::get<std::string>(v));
+        BOOST_TEST("foobar" == toml::get<std::string>(v));
+
+        const auto x = toml::get<std::string>(std::move(v));
+        BOOST_TEST("foobar" == x);
     }
     {
-        toml::value v("foo", toml::string_t::literal);
-        BOOST_CHECK_EQUAL("foo", toml::get<std::string>(v));
+        value_type v("foo", toml::string_t::literal);
+        BOOST_TEST("foo" == toml::get<std::string>(v));
         toml::get<std::string>(v) += "bar";
-        BOOST_CHECK_EQUAL("foobar", toml::get<std::string>(v));
+        BOOST_TEST("foobar" == toml::get<std::string>(v));
+
+        const auto x = toml::get<std::string>(std::move(v));
+        BOOST_TEST("foobar" == x);
     }
 
 #if __cplusplus >= 201703L
     {
-        toml::value v("foo", toml::string_t::basic);
-        BOOST_CHECK_EQUAL("foo", toml::get<std::string_view>(v));
+        value_type v("foo", toml::string_t::basic);
+        BOOST_TEST("foo" == toml::get<std::string_view>(v));
     }
     {
-        toml::value v("foo", toml::string_t::literal);
-        BOOST_CHECK_EQUAL("foo", toml::get<std::string_view>(v));
+        value_type v("foo", toml::string_t::literal);
+        BOOST_TEST("foo" == toml::get<std::string_view>(v));
     }
 #endif
 }
 
-BOOST_AUTO_TEST_CASE(test_get_toml_array)
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_toml_array, value_type, test_value_types)
 {
-    toml::value v(toml::array(0));
-    toml::get<toml::array>(v).push_back(toml::value(42));
-    toml::get<toml::array>(v).push_back(toml::value(54));
-    toml::get<toml::array>(v).push_back(toml::value(69));
-    toml::get<toml::array>(v).push_back(toml::value(72));
+    {
+        const value_type v{42, 54, 69, 72};
 
-    const std::vector<int>         vec = toml::get<std::vector<int>>(v);
-    const std::list<short>         lst = toml::get<std::list<short>>(v);
-    const std::deque<std::int64_t> deq = toml::get<std::deque<std::int64_t>>(v);
+        const std::vector<int>         vec = toml::get<std::vector<int>>(v);
+        const std::list<short>         lst = toml::get<std::list<short>>(v);
+        const std::deque<std::int64_t> deq = toml::get<std::deque<std::int64_t>>(v);
 
-    BOOST_CHECK_EQUAL(42, vec.at(0));
-    BOOST_CHECK_EQUAL(54, vec.at(1));
-    BOOST_CHECK_EQUAL(69, vec.at(2));
-    BOOST_CHECK_EQUAL(72, vec.at(3));
+        BOOST_TEST(42 == vec.at(0));
+        BOOST_TEST(54 == vec.at(1));
+        BOOST_TEST(69 == vec.at(2));
+        BOOST_TEST(72 == vec.at(3));
 
-    std::list<short>::const_iterator iter = lst.begin();
-    BOOST_CHECK_EQUAL(static_cast<short>(42), *(iter++));
-    BOOST_CHECK_EQUAL(static_cast<short>(54), *(iter++));
-    BOOST_CHECK_EQUAL(static_cast<short>(69), *(iter++));
-    BOOST_CHECK_EQUAL(static_cast<short>(72), *(iter++));
+        std::list<short>::const_iterator iter = lst.begin();
+        BOOST_TEST(static_cast<short>(42) == *(iter++));
+        BOOST_TEST(static_cast<short>(54) == *(iter++));
+        BOOST_TEST(static_cast<short>(69) == *(iter++));
+        BOOST_TEST(static_cast<short>(72) == *(iter++));
 
-    BOOST_CHECK_EQUAL(static_cast<std::int64_t>(42), deq.at(0));
-    BOOST_CHECK_EQUAL(static_cast<std::int64_t>(54), deq.at(1));
-    BOOST_CHECK_EQUAL(static_cast<std::int64_t>(69), deq.at(2));
-    BOOST_CHECK_EQUAL(static_cast<std::int64_t>(72), deq.at(3));
+        BOOST_TEST(static_cast<std::int64_t>(42) == deq.at(0));
+        BOOST_TEST(static_cast<std::int64_t>(54) == deq.at(1));
+        BOOST_TEST(static_cast<std::int64_t>(69) == deq.at(2));
+        BOOST_TEST(static_cast<std::int64_t>(72) == deq.at(3));
 
-    std::array<int, 4> ary = toml::get<std::array<int, 4>>(v);
-    BOOST_CHECK_EQUAL(static_cast<int>(42), ary.at(0));
-    BOOST_CHECK_EQUAL(static_cast<int>(54), ary.at(1));
-    BOOST_CHECK_EQUAL(static_cast<int>(69), ary.at(2));
-    BOOST_CHECK_EQUAL(static_cast<int>(72), ary.at(3));
+        std::array<int, 4> ary = toml::get<std::array<int, 4>>(v);
+        BOOST_TEST(42 == ary.at(0));
+        BOOST_TEST(54 == ary.at(1));
+        BOOST_TEST(69 == ary.at(2));
+        BOOST_TEST(72 == ary.at(3));
 
-    std::tuple<int, short, unsigned, long> tpl =
-        toml::get<std::tuple<int, short, unsigned, long>>(v);
-    BOOST_CHECK_EQUAL(static_cast<int     >(42), std::get<0>(tpl));
-    BOOST_CHECK_EQUAL(static_cast<short   >(54), std::get<1>(tpl));
-    BOOST_CHECK_EQUAL(static_cast<unsigned>(69), std::get<2>(tpl));
-    BOOST_CHECK_EQUAL(static_cast<long    >(72), std::get<3>(tpl));
+        std::tuple<int, short, unsigned, long> tpl =
+            toml::get<std::tuple<int, short, unsigned, long>>(v);
+        BOOST_TEST(                      42  == std::get<0>(tpl));
+        BOOST_TEST(static_cast<short   >(54) == std::get<1>(tpl));
+        BOOST_TEST(static_cast<unsigned>(69) == std::get<2>(tpl));
+        BOOST_TEST(static_cast<long    >(72) == std::get<3>(tpl));
 
-    toml::value p(toml::array{});
-    toml::get<toml::array>(p).push_back(toml::value(3.14));
-    toml::get<toml::array>(p).push_back(toml::value(2.71));
-    std::pair<double, double> pr = toml::get<std::pair<double, double> >(p);
-    BOOST_CHECK_EQUAL(3.14, pr.first);
-    BOOST_CHECK_EQUAL(2.71, pr.second);
+        const value_type p{3.14, 2.71};
+        std::pair<double, double> pr = toml::get<std::pair<double, double> >(p);
+        BOOST_TEST(3.14 == pr.first);
+        BOOST_TEST(2.71 == pr.second);
+    }
+
+    {
+        value_type v{42, 54, 69, 72};
+        const std::vector<int> vec = toml::get<std::vector<int>>(std::move(v));
+        BOOST_TEST(42 == vec.at(0));
+        BOOST_TEST(54 == vec.at(1));
+        BOOST_TEST(69 == vec.at(2));
+        BOOST_TEST(72 == vec.at(3));
+    }
+    {
+        value_type v{42, 54, 69, 72};
+        const std::deque<int> deq = toml::get<std::deque<int>>(std::move(v));
+        BOOST_TEST(42 == deq.at(0));
+        BOOST_TEST(54 == deq.at(1));
+        BOOST_TEST(69 == deq.at(2));
+        BOOST_TEST(72 == deq.at(3));
+    }
+    {
+        value_type v{42, 54, 69, 72};
+        const std::list<int> lst = toml::get<std::list<int>>(std::move(v));
+        std::list<int>::const_iterator iter = lst.begin();
+        BOOST_TEST(42 == *(iter++));
+        BOOST_TEST(54 == *(iter++));
+        BOOST_TEST(69 == *(iter++));
+        BOOST_TEST(72 == *(iter++));
+    }
+    {
+        value_type v{42, 54, 69, 72};
+        std::array<int, 4> ary = toml::get<std::array<int, 4>>(std::move(v));
+        BOOST_TEST(42 == ary.at(0));
+        BOOST_TEST(54 == ary.at(1));
+        BOOST_TEST(69 == ary.at(2));
+        BOOST_TEST(72 == ary.at(3));
+    }
+    {
+        value_type v{42, 54, 69, 72};
+        std::tuple<int, short, unsigned, long> tpl =
+            toml::get<std::tuple<int, short, unsigned, long>>(std::move(v));
+        BOOST_TEST(                      42  == std::get<0>(tpl));
+        BOOST_TEST(static_cast<short   >(54) == std::get<1>(tpl));
+        BOOST_TEST(static_cast<unsigned>(69) == std::get<2>(tpl));
+        BOOST_TEST(static_cast<long    >(72) == std::get<3>(tpl));
+    }
 }
 
-BOOST_AUTO_TEST_CASE(test_get_toml_array_of_array)
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_toml_array_of_array, value_type, test_value_types)
 {
-    toml::value v1(toml::array{});
-    toml::get<toml::array>(v1).push_back(toml::value(42));
-    toml::get<toml::array>(v1).push_back(toml::value(54));
-    toml::get<toml::array>(v1).push_back(toml::value(69));
-    toml::get<toml::array>(v1).push_back(toml::value(72));
+    {
+        const value_type v1{42, 54, 69, 72};
+        const value_type v2{"foo", "bar", "baz"};
+        const value_type v{v1, v2};
 
-    toml::value v2(toml::array{});
-    toml::get<toml::array>(v2).push_back(toml::value("foo"));
-    toml::get<toml::array>(v2).push_back(toml::value("bar"));
-    toml::get<toml::array>(v2).push_back(toml::value("baz"));
+        std::pair<std::vector<int>, std::vector<std::string>> p =
+            toml::get<std::pair<std::vector<int>, std::vector<std::string>>>(v);
 
-    toml::value v(toml::array(2));
-    toml::get<toml::array>(v).at(0) = v1;
-    toml::get<toml::array>(v).at(1) = v2;
+        BOOST_TEST(p.first.size() == 4u);
+        BOOST_TEST(p.first.at(0) == 42);
+        BOOST_TEST(p.first.at(1) == 54);
+        BOOST_TEST(p.first.at(2) == 69);
+        BOOST_TEST(p.first.at(3) == 72);
 
-    std::pair<std::vector<int>, std::vector<std::string>> p =
-        toml::get<std::pair<std::vector<int>, std::vector<std::string>>>(v);
+        BOOST_TEST(p.second.size() == 3u);
+        BOOST_TEST(p.second.at(0) == "foo");
+        BOOST_TEST(p.second.at(1) == "bar");
+        BOOST_TEST(p.second.at(2) == "baz");
 
-    BOOST_CHECK_EQUAL(p.first.at(0), 42);
-    BOOST_CHECK_EQUAL(p.first.at(1), 54);
-    BOOST_CHECK_EQUAL(p.first.at(2), 69);
-    BOOST_CHECK_EQUAL(p.first.at(3), 72);
+        std::tuple<std::vector<int>, std::vector<std::string>> t =
+            toml::get<std::tuple<std::vector<int>, std::vector<std::string>>>(v);
 
-    BOOST_CHECK_EQUAL(p.second.at(0), "foo");
-    BOOST_CHECK_EQUAL(p.second.at(1), "bar");
-    BOOST_CHECK_EQUAL(p.second.at(2), "baz");
+        BOOST_TEST(std::get<0>(t).at(0) == 42);
+        BOOST_TEST(std::get<0>(t).at(1) == 54);
+        BOOST_TEST(std::get<0>(t).at(2) == 69);
+        BOOST_TEST(std::get<0>(t).at(3) == 72);
 
-    std::tuple<std::vector<int>, std::vector<std::string>> t =
-        toml::get<std::tuple<std::vector<int>, std::vector<std::string>>>(v);
+        BOOST_TEST(std::get<1>(t).at(0) == "foo");
+        BOOST_TEST(std::get<1>(t).at(1) == "bar");
+        BOOST_TEST(std::get<1>(t).at(2) == "baz");
+    }
+    {
+        const value_type v1{42, 54, 69, 72};
+        const value_type v2{"foo", "bar", "baz"};
+        value_type v{v1, v2};
 
-    BOOST_CHECK_EQUAL(std::get<0>(t).at(0), 42);
-    BOOST_CHECK_EQUAL(std::get<0>(t).at(1), 54);
-    BOOST_CHECK_EQUAL(std::get<0>(t).at(2), 69);
-    BOOST_CHECK_EQUAL(std::get<0>(t).at(3), 72);
+        std::pair<std::vector<int>, std::vector<std::string>> p =
+            toml::get<std::pair<std::vector<int>, std::vector<std::string>>>(std::move(v));
 
-    BOOST_CHECK_EQUAL(std::get<1>(t).at(0), "foo");
-    BOOST_CHECK_EQUAL(std::get<1>(t).at(1), "bar");
-    BOOST_CHECK_EQUAL(std::get<1>(t).at(2), "baz");
+        BOOST_TEST(p.first.size() == 4u);
+        BOOST_TEST(p.first.at(0) == 42);
+        BOOST_TEST(p.first.at(1) == 54);
+        BOOST_TEST(p.first.at(2) == 69);
+        BOOST_TEST(p.first.at(3) == 72);
+
+        BOOST_TEST(p.second.size() == 3u);
+        BOOST_TEST(p.second.at(0) == "foo");
+        BOOST_TEST(p.second.at(1) == "bar");
+        BOOST_TEST(p.second.at(2) == "baz");
+    }
 }
 
-BOOST_AUTO_TEST_CASE(test_get_toml_table)
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_toml_table, value_type, test_value_types)
 {
-    toml::value v1(toml::table{
-            {"key1", 1},
-            {"key2", 2},
-            {"key3", 3},
-            {"key4", 4}
-            });
+    {
+        const value_type v1{
+                {"key1", 1},
+                {"key2", 2},
+                {"key3", 3},
+                {"key4", 4}
+            };
+
+        const auto v = toml::get<std::map<std::string, int>>(v1);
+        BOOST_TEST(v.at("key1") == 1);
+        BOOST_TEST(v.at("key2") == 2);
+        BOOST_TEST(v.at("key3") == 3);
+        BOOST_TEST(v.at("key4") == 4);
+    }
+    {
+        value_type v1{
+                {"key1", 1},
+                {"key2", 2},
+                {"key3", 3},
+                {"key4", 4}
+            };
+        const auto v = toml::get<std::map<std::string, int>>(std::move(v1));
+        BOOST_TEST(v.at("key1") == 1);
+        BOOST_TEST(v.at("key2") == 2);
+        BOOST_TEST(v.at("key3") == 3);
+        BOOST_TEST(v.at("key4") == 4);
+    }
 
-    const auto v = toml::get<std::map<std::string, int>>(v1);
-    BOOST_CHECK_EQUAL(v.at("key1"), 1);
-    BOOST_CHECK_EQUAL(v.at("key2"), 2);
-    BOOST_CHECK_EQUAL(v.at("key3"), 3);
-    BOOST_CHECK_EQUAL(v.at("key4"), 4);
 }
 
-
-BOOST_AUTO_TEST_CASE(test_get_toml_local_date)
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_toml_local_date, value_type, test_value_types)
 {
-    toml::value v1(toml::local_date{2018, toml::month_t::Apr, 1});
+    value_type v1(toml::local_date{2018, toml::month_t::Apr, 1});
     const auto date = std::chrono::system_clock::to_time_t(
             toml::get<std::chrono::system_clock::time_point>(v1));
 
@@ -305,20 +425,22 @@ BOOST_AUTO_TEST_CASE(test_get_toml_local_date)
     t.tm_sec  = 0;
     t.tm_isdst = -1;
     const auto c = std::mktime(&t);
-    BOOST_CHECK_EQUAL(c, date);
+    BOOST_TEST(c == date);
 }
 
-BOOST_AUTO_TEST_CASE(test_get_toml_local_time)
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_toml_local_time, value_type, test_value_types)
 {
-    toml::value v1(toml::local_time{12, 30, 45});
+    value_type v1(toml::local_time{12, 30, 45});
     const auto time = toml::get<std::chrono::seconds>(v1);
-    BOOST_CHECK(time == std::chrono::hours(12) +
-                        std::chrono::minutes(30) + std::chrono::seconds(45));
+    const bool result = time == std::chrono::hours(12)   +
+                                std::chrono::minutes(30) +
+                                std::chrono::seconds(45);
+    BOOST_TEST(result);
 }
 
-BOOST_AUTO_TEST_CASE(test_get_toml_local_datetime)
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_toml_local_datetime, value_type, test_value_types)
 {
-    toml::value v1(toml::local_datetime(
+    value_type v1(toml::local_datetime(
                 toml::local_date{2018, toml::month_t::Apr, 1},
                 toml::local_time{12, 30, 45}));
 
@@ -333,13 +455,13 @@ BOOST_AUTO_TEST_CASE(test_get_toml_local_datetime)
     t.tm_sec  = 45;
     t.tm_isdst = -1;
     const auto c = std::mktime(&t);
-    BOOST_CHECK_EQUAL(c, date);
+    BOOST_TEST(c == date);
 }
 
-BOOST_AUTO_TEST_CASE(test_get_toml_offset_datetime)
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_toml_offset_datetime, value_type, test_value_types)
 {
     {
-    toml::value v1(toml::offset_datetime(
+    value_type v1(toml::offset_datetime(
                 toml::local_date{2018, toml::month_t::Apr, 1},
                 toml::local_time{12, 30, 0},
                 toml::time_offset{9, 0}));
@@ -351,18 +473,18 @@ BOOST_AUTO_TEST_CASE(test_get_toml_offset_datetime)
 
     // get time_t as gmtime (2018-04-01T03:30:00Z)
     const auto tmp = std::gmtime(std::addressof(timet)); // XXX not threadsafe!
-    BOOST_CHECK(tmp);
+    BOOST_TEST(tmp);
     const auto tm = *tmp;
-    BOOST_CHECK_EQUAL(tm.tm_year + 1900, 2018);
-    BOOST_CHECK_EQUAL(tm.tm_mon  + 1,       4);
-    BOOST_CHECK_EQUAL(tm.tm_mday,           1);
-    BOOST_CHECK_EQUAL(tm.tm_hour,           3);
-    BOOST_CHECK_EQUAL(tm.tm_min,           30);
-    BOOST_CHECK_EQUAL(tm.tm_sec,            0);
+    BOOST_TEST(tm.tm_year + 1900 == 2018);
+    BOOST_TEST(tm.tm_mon  + 1 ==       4);
+    BOOST_TEST(tm.tm_mday ==           1);
+    BOOST_TEST(tm.tm_hour ==           3);
+    BOOST_TEST(tm.tm_min ==           30);
+    BOOST_TEST(tm.tm_sec ==            0);
     }
 
     {
-    toml::value v1(toml::offset_datetime(
+    value_type v1(toml::offset_datetime(
                 toml::local_date{2018, toml::month_t::Apr, 1},
                 toml::local_time{12, 30, 0},
                 toml::time_offset{-8, 0}));
@@ -374,14 +496,14 @@ BOOST_AUTO_TEST_CASE(test_get_toml_offset_datetime)
 
     // get time_t as gmtime (2018-04-01T03:30:00Z)
     const auto tmp = std::gmtime(std::addressof(timet)); // XXX not threadsafe!
-    BOOST_CHECK(tmp);
+    BOOST_TEST(tmp);
     const auto tm = *tmp;
-    BOOST_CHECK_EQUAL(tm.tm_year + 1900, 2018);
-    BOOST_CHECK_EQUAL(tm.tm_mon  + 1,       4);
-    BOOST_CHECK_EQUAL(tm.tm_mday,           1);
-    BOOST_CHECK_EQUAL(tm.tm_hour,          20);
-    BOOST_CHECK_EQUAL(tm.tm_min,           30);
-    BOOST_CHECK_EQUAL(tm.tm_sec,            0);
+    BOOST_TEST(tm.tm_year + 1900 == 2018);
+    BOOST_TEST(tm.tm_mon  + 1 ==       4);
+    BOOST_TEST(tm.tm_mday ==           1);
+    BOOST_TEST(tm.tm_hour ==          20);
+    BOOST_TEST(tm.tm_min ==           30);
+    BOOST_TEST(tm.tm_sec ==            0);
     }
 }
 

tests/test_get_or.cpp

@@ -0,0 +1,452 @@
+#define BOOST_TEST_MODULE "test_get_or"
+#ifdef UNITTEST_FRAMEWORK_LIBRARY_EXIST
+#include <boost/test/unit_test.hpp>
+#else
+#define BOOST_TEST_NO_LIB
+#include <boost/test/included/unit_test.hpp>
+#endif
+#include <toml.hpp>
+#include <map>
+#include <unordered_map>
+#include <list>
+#include <deque>
+#include <array>
+#include <tuple>
+#if __cplusplus >= 201703L
+#include <string_view>
+#endif
+
+using test_value_types = std::tuple<
+    toml::value,
+    toml::basic_value<toml::preserve_comments>,
+    toml::basic_value<toml::discard_comments,  std::map, std::deque>,
+    toml::basic_value<toml::preserve_comments, std::map, std::deque>
+>;
+
+namespace test
+{
+// to compare result values in BOOST_TEST().
+//
+// BOOST_TEST outputs the expected and actual values. Thus it includes the
+// output stream operator inside. To compile it, we need operator<<s for
+// containers to compare.
+template<typename charT, typename traits, typename T, typename Alloc>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os, const std::vector<T, Alloc>& v)
+{
+    os << "[ ";
+    for(const auto& i : v) {os << i << ' ';}
+    os << ']';
+    return os;
+}
+template<typename charT, typename traits, typename T, typename Alloc>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os, const std::deque<T, Alloc>& v)
+{
+    os << "[ ";
+    for(const auto& i : v) {os << i << ' ';}
+    os << ']';
+    return os;
+}
+template<typename charT, typename traits, typename T, typename Alloc>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os, const std::list<T, Alloc>& v)
+{
+    os << "[ ";
+    for(const auto& i : v) {os << i << ' ';}
+    os << ']';
+    return os;
+}
+template<typename charT, typename traits,
+         typename Key, typename Value, typename Comp, typename Alloc>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os,
+           const std::map<Key, Value, Comp, Alloc>& v)
+{
+    os << "[ ";
+    for(const auto& i : v) {os << '{' << i.first << ", " << i.second << "} ";}
+    os << ']';
+    return os;
+}
+template<typename charT, typename traits,
+         typename Key, typename Value, typename Hash, typename Eq, typename Alloc>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os,
+           const std::unordered_map<Key, Value, Hash, Eq, Alloc>& v)
+{
+    os << "[ ";
+    for(const auto& i : v) {os << '{' << i.first << ", " << i.second << "} ";}
+    os << ']';
+    return os;
+}
+} // test
+
+#define TOML11_TEST_GET_OR_EXACT(toml_type, init_expr, opt_expr)\
+    {                                                           \
+        using namespace test;                                   \
+        const toml::toml_type init init_expr ;                  \
+        const toml::toml_type opt  opt_expr ;                   \
+        const value_type v(init);                               \
+        BOOST_TEST(init != opt);                                \
+        BOOST_TEST(init == toml::get_or(v, opt));               \
+    }                                                           \
+    /**/
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_or_exact, value_type, test_value_types)
+{
+    TOML11_TEST_GET_OR_EXACT(boolean,         ( true), (false))
+    TOML11_TEST_GET_OR_EXACT(integer,         (   42), (   54))
+    TOML11_TEST_GET_OR_EXACT(floating,        ( 3.14), ( 2.71))
+    TOML11_TEST_GET_OR_EXACT(string,          ("foo"), ("bar"))
+    TOML11_TEST_GET_OR_EXACT(local_time,      (12, 30, 45), (6, 0, 30))
+    TOML11_TEST_GET_OR_EXACT(local_date,      (2019, toml::month_t::Apr, 1),
+                                              (1999, toml::month_t::Jan, 2))
+    TOML11_TEST_GET_OR_EXACT(local_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30))
+            )
+    TOML11_TEST_GET_OR_EXACT(offset_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45), toml::time_offset( 9, 0)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30), toml::time_offset(-3, 0))
+            )
+    {
+        const typename value_type::array_type init{1,2,3,4,5};
+        const typename value_type::array_type opt {6,7,8,9,10};
+        const value_type v(init);
+        BOOST_TEST(init != opt);
+        BOOST_TEST(init == toml::get_or(v, opt));
+    }
+    {
+        const typename value_type::table_type init{{"key1", 42}, {"key2", "foo"}};
+        const typename value_type::table_type opt {{"key1", 54}, {"key2", "bar"}};
+        const value_type v(init);
+        BOOST_TEST(init != opt);
+        BOOST_TEST(init == toml::get_or(v, opt));
+    }
+}
+#undef TOML11_TEST_GET_OR_EXACT
+
+#define TOML11_TEST_GET_OR_MOVE_EXACT(toml_type, init_expr, opt_expr)\
+    {                                                                \
+        using namespace test;                                        \
+        const toml::toml_type init init_expr ;                       \
+        toml::toml_type       opt  opt_expr ;                        \
+        value_type v(init);                                          \
+        BOOST_TEST(init != opt);                                     \
+        const auto opt_ = toml::get_or(std::move(v), std::move(opt));\
+        BOOST_TEST(init == opt_);                                    \
+    }                                                                \
+    /**/
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_or_move, value_type, test_value_types)
+{
+    TOML11_TEST_GET_OR_MOVE_EXACT(boolean,         ( true), (false))
+    TOML11_TEST_GET_OR_MOVE_EXACT(integer,         (   42), (   54))
+    TOML11_TEST_GET_OR_MOVE_EXACT(floating,        ( 3.14), ( 2.71))
+    TOML11_TEST_GET_OR_MOVE_EXACT(string,          ("foo"), ("bar"))
+    TOML11_TEST_GET_OR_MOVE_EXACT(local_time,      (12, 30, 45), (6, 0, 30))
+    TOML11_TEST_GET_OR_MOVE_EXACT(local_date,      (2019, toml::month_t::Apr, 1),
+                                                   (1999, toml::month_t::Jan, 2))
+    TOML11_TEST_GET_OR_MOVE_EXACT(local_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30))
+            )
+    TOML11_TEST_GET_OR_MOVE_EXACT(offset_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45), toml::time_offset( 9, 0)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30), toml::time_offset(-3, 0))
+            )
+    {
+        const typename value_type::array_type init{1,2,3,4,5};
+        typename value_type::array_type opt {6,7,8,9,10};
+        value_type v(init);
+        BOOST_TEST(init != opt);
+        const auto opt_ = toml::get_or(std::move(v), std::move(opt));
+        BOOST_TEST(init == opt_);
+    }
+    {
+        const typename value_type::table_type init{{"key1", 42}, {"key2", "foo"}};
+        typename value_type::table_type opt {{"key1", 54}, {"key2", "bar"}};
+        value_type v(init);
+        BOOST_TEST(init != opt);
+        const auto opt_ = toml::get_or(std::move(v), std::move(opt));
+        BOOST_TEST(init == opt_);
+    }
+}
+#undef TOML11_TEST_GET_OR_MOVE_EXACT
+
+
+#define TOML11_TEST_GET_OR_MODIFY(toml_type, init_expr, opt_expr)\
+    {                                                            \
+        using namespace test;                                    \
+        const toml::toml_type init init_expr ;                   \
+        toml::toml_type       opt1 opt_expr ;                    \
+        toml::toml_type       opt2 opt_expr ;                    \
+        value_type v(init);                                      \
+        BOOST_TEST(init != opt1);                                \
+        toml::get_or(v, opt2) = opt1;                            \
+        BOOST_TEST(opt1 == toml::get<toml::toml_type>(v));       \
+    }                                                            \
+    /**/
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_or_modify, value_type, test_value_types)
+{
+    TOML11_TEST_GET_OR_MODIFY(boolean,         ( true), (false))
+    TOML11_TEST_GET_OR_MODIFY(integer,         (   42), (   54))
+    TOML11_TEST_GET_OR_MODIFY(floating,        ( 3.14), ( 2.71))
+    TOML11_TEST_GET_OR_MODIFY(string,          ("foo"), ("bar"))
+    TOML11_TEST_GET_OR_MODIFY(local_time,      (12, 30, 45), (6, 0, 30))
+    TOML11_TEST_GET_OR_MODIFY(local_date,      (2019, toml::month_t::Apr, 1),
+                                              (1999, toml::month_t::Jan, 2))
+    TOML11_TEST_GET_OR_MODIFY(local_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30))
+            )
+    TOML11_TEST_GET_OR_MODIFY(offset_datetime,
+            (toml::local_date(2019, toml::month_t::Apr, 1), toml::local_time(12, 30, 45), toml::time_offset( 9, 0)),
+            (toml::local_date(1999, toml::month_t::Jan, 2), toml::local_time( 6,  0, 30), toml::time_offset(-3, 0))
+            )
+    {
+        typename value_type::array_type init{1,2,3,4,5};
+        typename value_type::array_type opt1{6,7,8,9,10};
+        typename value_type::array_type opt2{6,7,8,9,10};
+        BOOST_TEST(init != opt1);
+        value_type v(init);
+        toml::get_or(v, opt2) = opt1;
+        BOOST_TEST(opt1 == toml::get<typename value_type::array_type>(v));
+    }
+    {
+        typename value_type::table_type init{{"key1", 42}, {"key2", "foo"}};
+        typename value_type::table_type opt1{{"key1", 54}, {"key2", "bar"}};
+        typename value_type::table_type opt2{{"key1", 54}, {"key2", "bar"}};
+        value_type v(init);
+        BOOST_TEST(init != opt1);
+        toml::get_or(v, opt2) = opt1;
+        BOOST_TEST(opt1 == toml::get<typename value_type::table_type>(v));
+    }
+}
+#undef TOML11_TEST_GET_OR_MODIFY
+
+#define TOML11_TEST_GET_OR_FALLBACK(init_type, opt_type)  \
+    {                                                     \
+        using namespace test;                             \
+        value_type v(init_type);                          \
+        BOOST_TEST(opt_type == toml::get_or(v, opt_type));\
+    }                                                     \
+    /**/
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(test_get_or_fallback, value_type, test_value_types)
+{
+    const toml::boolean         boolean        (true);
+    const toml::integer         integer        (42);
+    const toml::floating        floating       (3.14);
+    const toml::string          string         ("foo");
+    const toml::local_time      local_time     (12, 30, 45);
+    const toml::local_date      local_date     (2019, toml::month_t::Apr, 1);
+    const toml::local_datetime  local_datetime (
+            toml::local_date(2019, toml::month_t::Apr, 1),
+            toml::local_time(12, 30, 45));
+    const toml::offset_datetime offset_datetime(
+            toml::local_date(2019, toml::month_t::Apr, 1),
+            toml::local_time(12, 30, 45), toml::time_offset( 9, 0));
+
+    using array_type = typename value_type::array_type;
+    using table_type = typename value_type::table_type;
+    const array_type array{1, 2, 3, 4, 5};
+    const table_type table{{"key1", 42}, {"key2", "foo"}};
+
+    TOML11_TEST_GET_OR_FALLBACK(boolean, integer        );
+    TOML11_TEST_GET_OR_FALLBACK(boolean, floating       );
+    TOML11_TEST_GET_OR_FALLBACK(boolean, string         );
+    TOML11_TEST_GET_OR_FALLBACK(boolean, local_time     );
+    TOML11_TEST_GET_OR_FALLBACK(boolean, local_date     );
+    TOML11_TEST_GET_OR_FALLBACK(boolean, local_datetime );
+    TOML11_TEST_GET_OR_FALLBACK(boolean, offset_datetime);
+    TOML11_TEST_GET_OR_FALLBACK(boolean, array          );
+    TOML11_TEST_GET_OR_FALLBACK(boolean, table          );
+
+    TOML11_TEST_GET_OR_FALLBACK(integer, boolean        );
+    TOML11_TEST_GET_OR_FALLBACK(integer, floating       );
+    TOML11_TEST_GET_OR_FALLBACK(integer, string         );
+    TOML11_TEST_GET_OR_FALLBACK(integer, local_time     );
+    TOML11_TEST_GET_OR_FALLBACK(integer, local_date     );
+    TOML11_TEST_GET_OR_FALLBACK(integer, local_datetime );
+    TOML11_TEST_GET_OR_FALLBACK(integer, offset_datetime);
+    TOML11_TEST_GET_OR_FALLBACK(integer, array          );
+    TOML11_TEST_GET_OR_FALLBACK(integer, table          );
+
+    TOML11_TEST_GET_OR_FALLBACK(floating, boolean        );
+    TOML11_TEST_GET_OR_FALLBACK(floating, integer        );
+    TOML11_TEST_GET_OR_FALLBACK(floating, string         );
+    TOML11_TEST_GET_OR_FALLBACK(floating, local_time     );
+    TOML11_TEST_GET_OR_FALLBACK(floating, local_date     );
+    TOML11_TEST_GET_OR_FALLBACK(floating, local_datetime );
+    TOML11_TEST_GET_OR_FALLBACK(floating, offset_datetime);
+    TOML11_TEST_GET_OR_FALLBACK(floating, array          );
+    TOML11_TEST_GET_OR_FALLBACK(floating, table          );
+
+    TOML11_TEST_GET_OR_FALLBACK(string, boolean        );
+    TOML11_TEST_GET_OR_FALLBACK(string, integer        );
+    TOML11_TEST_GET_OR_FALLBACK(string, floating       );
+    TOML11_TEST_GET_OR_FALLBACK(string, local_time     );
+    TOML11_TEST_GET_OR_FALLBACK(string, local_date     );
+    TOML11_TEST_GET_OR_FALLBACK(string, local_datetime );
+    TOML11_TEST_GET_OR_FALLBACK(string, offset_datetime);
+    TOML11_TEST_GET_OR_FALLBACK(string, array          );
+    TOML11_TEST_GET_OR_FALLBACK(string, table          );
+
+    TOML11_TEST_GET_OR_FALLBACK(local_time, boolean        );
+    TOML11_TEST_GET_OR_FALLBACK(local_time, integer        );
+    TOML11_TEST_GET_OR_FALLBACK(local_time, floating       );
+    TOML11_TEST_GET_OR_FALLBACK(local_time, string         );
+    TOML11_TEST_GET_OR_FALLBACK(local_time, local_date     );
+    TOML11_TEST_GET_OR_FALLBACK(local_time, local_datetime );
+    TOML11_TEST_GET_OR_FALLBACK(local_time, offset_datetime);
+    TOML11_TEST_GET_OR_FALLBACK(local_time, array          );
+    TOML11_TEST_GET_OR_FALLBACK(local_time, table          );
+
+    TOML11_TEST_GET_OR_FALLBACK(local_date, boolean        );
+    TOML11_TEST_GET_OR_FALLBACK(local_date, integer        );
+    TOML11_TEST_GET_OR_FALLBACK(local_date, floating       );
+    TOML11_TEST_GET_OR_FALLBACK(local_date, string         );
+    TOML11_TEST_GET_OR_FALLBACK(local_date, local_time     );
+    TOML11_TEST_GET_OR_FALLBACK(local_date, local_datetime );
+    TOML11_TEST_GET_OR_FALLBACK(local_date, offset_datetime);
+    TOML11_TEST_GET_OR_FALLBACK(local_date, array          );
+    TOML11_TEST_GET_OR_FALLBACK(local_date, table          );
+
+    TOML11_TEST_GET_OR_FALLBACK(local_datetime, boolean        );
+    TOML11_TEST_GET_OR_FALLBACK(local_datetime, integer        );
+    TOML11_TEST_GET_OR_FALLBACK(local_datetime, floating       );
+    TOML11_TEST_GET_OR_FALLBACK(local_datetime, string         );
+    TOML11_TEST_GET_OR_FALLBACK(local_datetime, local_time     );
+    TOML11_TEST_GET_OR_FALLBACK(local_datetime, local_date     );
+    TOML11_TEST_GET_OR_FALLBACK(local_datetime, offset_datetime);
+    TOML11_TEST_GET_OR_FALLBACK(local_datetime, array          );
+    TOML11_TEST_GET_OR_FALLBACK(local_datetime, table          );
+
+    TOML11_TEST_GET_OR_FALLBACK(offset_datetime, boolean        );
+    TOML11_TEST_GET_OR_FALLBACK(offset_datetime, integer        );
+    TOML11_TEST_GET_OR_FALLBACK(offset_datetime, floating       );
+    TOML11_TEST_GET_OR_FALLBACK(offset_datetime, string         );
+    TOML11_TEST_GET_OR_FALLBACK(offset_datetime, local_time     );
+    TOML11_TEST_GET_OR_FALLBACK(offset_datetime, local_date     );
+    TOML11_TEST_GET_OR_FALLBACK(offset_datetime, local_datetime );
+    TOML11_TEST_GET_OR_FALLBACK(offset_datetime, array          );
+    TOML11_TEST_GET_OR_FALLBACK(offset_datetime, table          );
+
+    TOML11_TEST_GET_OR_FALLBACK(array, boolean        );
+    TOML11_TEST_GET_OR_FALLBACK(array, integer        );
+    TOML11_TEST_GET_OR_FALLBACK(array, floating       );
+    TOML11_TEST_GET_OR_FALLBACK(array, string         );
+    TOML11_TEST_GET_OR_FALLBACK(array, local_time     );
+    TOML11_TEST_GET_OR_FALLBACK(array, local_date     );
+    TOML11_TEST_GET_OR_FALLBACK(array, local_datetime );
+    TOML11_TEST_GET_OR_FALLBACK(array, offset_datetime);
+    TOML11_TEST_GET_OR_FALLBACK(array, table          );
+
+    TOML11_TEST_GET_OR_FALLBACK(table, boolean        );
+    TOML11_TEST_GET_OR_FALLBACK(table, integer        );
+    TOML11_TEST_GET_OR_FALLBACK(table, floating       );
+    TOML11_TEST_GET_OR_FALLBACK(table, string         );
+    TOML11_TEST_GET_OR_FALLBACK(table, local_time     );
+    TOML11_TEST_GET_OR_FALLBACK(table, local_date     );
+    TOML11_TEST_GET_OR_FALLBACK(table, local_datetime );
+    TOML11_TEST_GET_OR_FALLBACK(table, offset_datetime);
+    TOML11_TEST_GET_OR_FALLBACK(table, array          );
+}
+#undef TOML11_TEST_GET_OR_FALLBACK
+
+BOOST_AUTO_TEST_CASE(test_get_or_integer)
+{
+    {
+        toml::value v1(42);
+        toml::value v2(3.14);
+        BOOST_TEST(42u == toml::get_or(v1, 0u));
+        BOOST_TEST(0u ==  toml::get_or(v2, 0u));
+    }
+    {
+        toml::value v1(42);
+        toml::value v2(3.14);
+        BOOST_TEST(42u == toml::get_or(std::move(v1), 0u));
+        BOOST_TEST(0u ==  toml::get_or(std::move(v2), 0u));
+    }
+
+}
+
+BOOST_AUTO_TEST_CASE(test_get_or_floating)
+{
+    {
+        toml::value v1(42);
+        toml::value v2(3.14);
+        BOOST_TEST(2.71f == toml::get_or(v1, 2.71f));
+        BOOST_TEST(static_cast<float>(v2.as_floating()) == toml::get_or(v2, 2.71f));
+    }
+    {
+        toml::value v1(42);
+        toml::value v2(3.14);
+        BOOST_TEST(2.71f                    == toml::get_or(std::move(v1), 2.71f));
+        BOOST_TEST(static_cast<float>(3.14) == toml::get_or(std::move(v2), 2.71f));
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_get_or_string)
+{
+    {
+        toml::value v1("foobar");
+        toml::value v2(42);
+
+        std::string       s1("bazqux");
+        const std::string s2("bazqux");
+
+        BOOST_TEST("foobar" == toml::get_or(v1, s1));
+        BOOST_TEST("bazqux" == toml::get_or(v2, s1));
+
+        std::string& v1r = toml::get_or(v1, s1);
+        std::string& s1r = toml::get_or(v2, s1);
+
+        BOOST_TEST("foobar" == v1r);
+        BOOST_TEST("bazqux" == s1r);
+
+        BOOST_TEST("foobar" == toml::get_or(v1, s2));
+        BOOST_TEST("bazqux" == toml::get_or(v2, s2));
+
+        BOOST_TEST("foobar" == toml::get_or(v1, std::move(s1)));
+        BOOST_TEST("bazqux" == toml::get_or(v2, std::move(s1)));
+    }
+    {
+        toml::value v1("foobar");
+        toml::value v2(42);
+
+        std::string       s1("bazqux");
+        const std::string s2("bazqux");
+
+        BOOST_TEST("foobar" == toml::get_or(std::move(v1), s1));
+        BOOST_TEST("bazqux" == toml::get_or(std::move(v2), s1));
+    }
+    {
+        toml::value v1("foobar");
+        toml::value v2(42);
+
+        BOOST_TEST("foobar" == toml::get_or(v1, "bazqux"));
+        BOOST_TEST("bazqux" == toml::get_or(v2, "bazqux"));
+
+        const char* lit = "bazqux";
+        BOOST_TEST("foobar" == toml::get_or(v1, lit));
+        BOOST_TEST("bazqux" == toml::get_or(v2, lit));
+    }
+    {
+        toml::value v1("foobar");
+        toml::value v2(42);
+
+        BOOST_TEST("foobar" == toml::get_or(std::move(v1), "bazqux"));
+        BOOST_TEST("bazqux" == toml::get_or(std::move(v2), "bazqux"));
+    }
+    {
+        toml::value v1("foobar");
+        toml::value v2(42);
+
+        const char* lit = "bazqux";
+        BOOST_TEST("foobar" == toml::get_or(v1, lit));
+        BOOST_TEST("bazqux" == toml::get_or(v2, lit));
+    }
+
+}

tests/test_get_related_func.cpp

@@ -1,254 +0,0 @@
-#define BOOST_TEST_MODULE "test_get_or"
-#ifdef UNITTEST_FRAMEWORK_LIBRARY_EXIST
-#include <boost/test/unit_test.hpp>
-#else
-#define BOOST_TEST_NO_LIB
-#include <boost/test/included/unit_test.hpp>
-#endif
-#include <toml.hpp>
-#include <map>
-#include <unordered_map>
-#include <list>
-#include <deque>
-#include <array>
-
-BOOST_AUTO_TEST_CASE(test_find)
-{
-    {
-        toml::value v(true);
-        bool thrown = false;
-        try
-        {
-            toml::find<toml::boolean>(v, "key");
-        }
-        catch(toml::type_error const& te)
-        {
-            thrown = true;
-        }
-        BOOST_CHECK(thrown);
-    }
-
-    {
-        toml::table v{{"num", 42}};
-        BOOST_CHECK_EQUAL(42, toml::find<int>(v, "num"));
-        toml::find<toml::integer>(v, "num") = 54;
-        BOOST_CHECK_EQUAL(54, toml::find<int>(v, "num"));
-    }
-
-    {
-        toml::value v = toml::table{{"num", 42}};
-        BOOST_CHECK_EQUAL(42, toml::find<int>(v, "num"));
-        toml::find<toml::integer>(v, "num") = 54;
-        BOOST_CHECK_EQUAL(54, toml::find<int>(v, "num"));
-    }
-}
-
-BOOST_AUTO_TEST_CASE(test_get_or)
-{
-    // requires conversion int -> uint
-    {
-        toml::value v1(42);
-        toml::value v2(3.14);
-        BOOST_CHECK_EQUAL(42u, toml::get_or(v1, 0u));
-        BOOST_CHECK_EQUAL(0u,  toml::get_or(v2, 0u));
-    }
-
-    // exact toml type
-    {
-        toml::value v1(42);
-        toml::value v2(3.14);
-
-        toml::integer opt(0);
-        BOOST_CHECK_EQUAL(42, toml::get_or(v1, opt));
-        BOOST_CHECK_EQUAL(0,  toml::get_or(v2, opt));
-
-        toml::value v3("foobar");
-        toml::string s("bazqux");
-
-        BOOST_CHECK_EQUAL("foobar", toml::get_or(v3, s));
-        BOOST_CHECK_EQUAL("bazqux", toml::get_or(v1, s));
-
-    }
-
-    // std::string
-    {
-        toml::value v1("foobar");
-        toml::value v2(42);
-
-        std::string       s1("bazqux");
-        const std::string s2("bazqux");
-
-        BOOST_CHECK_EQUAL("foobar", toml::get_or(v1, s1));
-        BOOST_CHECK_EQUAL("bazqux", toml::get_or(v2, s1));
-
-        std::string& v1r = toml::get_or(v1, s1);
-        std::string& s1r = toml::get_or(v2, s1);
-
-        BOOST_CHECK_EQUAL("foobar", v1r);
-        BOOST_CHECK_EQUAL("bazqux", s1r);
-
-        BOOST_CHECK_EQUAL("foobar", toml::get_or(v1, s2));
-        BOOST_CHECK_EQUAL("bazqux", toml::get_or(v2, s2));
-
-        BOOST_CHECK_EQUAL("foobar", toml::get_or(v1, std::move(s1)));
-        BOOST_CHECK_EQUAL("bazqux", toml::get_or(v2, std::move(s1)));
-    }
-
-    // string literal
-    {
-        toml::value v1("foobar");
-        toml::value v2(42);
-
-        BOOST_CHECK_EQUAL("foobar", toml::get_or(v1, "bazqux"));
-        BOOST_CHECK_EQUAL("bazqux", toml::get_or(v2, "bazqux"));
-
-        const char* lit = "bazqux";
-        BOOST_CHECK_EQUAL("foobar", toml::get_or(v1, lit));
-        BOOST_CHECK_EQUAL("bazqux", toml::get_or(v2, lit));
-    }
-}
-
-BOOST_AUTO_TEST_CASE(test_find_or)
-{
-    // ========================================================================
-    // pass toml::value
-    //
-    // requires conversion int -> uint
-    {
-        toml::table v{{"num", 42}};
-        BOOST_CHECK_EQUAL(42u, toml::find_or(v, "num", 0u));
-        BOOST_CHECK_EQUAL(0u,  toml::find_or(v, "foo", 0u));
-    }
-    // exact toml type
-    {
-        toml::table v1{{"key", 42  }};
-        toml::table v2{{"key", 3.14}};
-        toml::table v3{{"not", "key"}};
-
-        toml::integer opt(0);
-        BOOST_CHECK_EQUAL(42, toml::find_or(v1, "key", opt));
-        BOOST_CHECK_EQUAL(0,  toml::find_or(v2, "key", opt));
-        BOOST_CHECK_EQUAL(0,  toml::find_or(v3, "key", opt));
-
-        toml::table v4{{"str", "foobar"}};
-        toml::string s("bazqux");
-
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(v4, "str", s));
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(v1, "str", s));
-    }
-    // std::string
-    {
-        toml::table v1{{"key", "foobar"}};
-        toml::table v2{{"key", 42}};
-
-        std::string       s1("bazqux");
-        const std::string s2("bazqux");
-
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(v1, "key", s1));
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(v2, "key", s1));
-
-        std::string& v1r = toml::find_or(v1, "key", s1);
-        std::string& s1r = toml::find_or(v2, "key", s1);
-
-        BOOST_CHECK_EQUAL("foobar", v1r);
-        BOOST_CHECK_EQUAL("bazqux", s1r);
-
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(v1, "key", s2));
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(v2, "key", s2));
-
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(std::move(v1), "key", std::move(s1)));
-        s1 = "bazqux"; // restoring moved value
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(std::move(v2), "key", std::move(s1)));
-    }
-    // string literal
-    {
-        toml::table v1{{"key", "foobar"}};
-        toml::table v2{{"key",42}};
-
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(v1, "key", "bazqux"));
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(v2, "key", "bazqux"));
-
-        const char* lit = "bazqux";
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(v1, "key", lit));
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(v2, "key", lit));
-    }
-
-    // ========================================================================
-    // pass toml::value
-    //
-    // requires conversion int -> uint
-    {
-        toml::table v = toml::table{{"num", 42}};
-        BOOST_CHECK_EQUAL(42u, toml::find_or(v, "num", 0u));
-        BOOST_CHECK_EQUAL(0u,  toml::find_or(v, "foo", 0u));
-    }
-    // exact toml type
-    {
-        toml::value v1 = toml::table{{"key", 42  }};
-        toml::value v2 = toml::table{{"key", 3.14}};
-        toml::value v3 = toml::table{{"not", "key"}};
-
-        BOOST_CHECK_EQUAL(42, toml::find_or(v1, "key", toml::integer(0)));
-        BOOST_CHECK_EQUAL( 0, toml::find_or(v2, "key", toml::integer(0)));
-        BOOST_CHECK_EQUAL( 0, toml::find_or(v3, "key", toml::integer(0)));
-
-        toml::value v4 = toml::table{{"str", "foobar"}};
-        toml::string s("bazqux");
-
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(v4, "str", s));
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(v1, "str", s));
-    }
-    // std::string
-    {
-        toml::value v1 = toml::table{{"key", "foobar"}};
-        toml::value v2 = toml::table{{"key", 42}};
-
-        std::string       s1("bazqux");
-        const std::string s2("bazqux");
-
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(v1, "key", s1));
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(v2, "key", s1));
-
-        std::string& v1r = toml::find_or(v1, "key", s1);
-        std::string& s1r = toml::find_or(v2, "key", s1);
-
-        BOOST_CHECK_EQUAL("foobar", v1r);
-        BOOST_CHECK_EQUAL("bazqux", s1r);
-
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(v1, "key", s2));
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(v2, "key", s2));
-
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(std::move(v1), "key", std::move(s1)));
-        s1 = "bazqux"; // restoring moved value
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(std::move(v2), "key", std::move(s1)));
-    }
-    // string literal
-    {
-        toml::value v1 = toml::table{{"key", "foobar"}};
-        toml::value v2 = toml::table{{"key",42}};
-
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(v1, "key", "bazqux"));
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(v2, "key", "bazqux"));
-
-        const char* lit = "bazqux";
-        BOOST_CHECK_EQUAL("foobar", toml::find_or(v1, "key", lit));
-        BOOST_CHECK_EQUAL("bazqux", toml::find_or(v2, "key", lit));
-    }
-}
-
-BOOST_AUTO_TEST_CASE(test_expect)
-{
-    {
-        toml::value v1(42);
-        toml::value v2(3.14);
-        const auto v1_or_0 = toml::expect<int>(v1).unwrap_or(0);
-        const auto v2_or_0 = toml::expect<int>(v2).unwrap_or(0);
-        BOOST_CHECK_EQUAL(42, v1_or_0);
-        BOOST_CHECK_EQUAL( 0, v2_or_0);
-
-        const auto v1_or_none = toml::expect<int>(v1).map([](int i){return std::to_string(i);}).unwrap_or(std::string("none"));
-        const auto v2_or_none = toml::expect<int>(v2).map([](int i){return std::to_string(i);}).unwrap_or(std::string("none"));
-        BOOST_CHECK_EQUAL("42",   v1_or_none);
-        BOOST_CHECK_EQUAL("none", v2_or_none);
-    }
-}

tests/test_lex_aux.hpp

@@ -8,19 +8,19 @@
 do {                                                                           \
     const std::string token   (tkn);                                           \
     const std::string expected(expct);                                         \
-    toml::detail::location<std::string> loc("test", token);                    \
+    toml::detail::location loc("test", token);                                 \
     const auto result = lxr::invoke(loc);                                      \
-    BOOST_CHECK(result.is_ok());                                               \
+    BOOST_TEST(result.is_ok());                                                \
     if(result.is_ok()){                                                        \
-    const auto region = result.unwrap();                                       \
-    BOOST_CHECK_EQUAL(region.str(), expected);                                 \
-    BOOST_CHECK_EQUAL(region.str().size(), expected.size());                   \
-    BOOST_CHECK_EQUAL(static_cast<std::size_t>(std::distance(                  \
-                    loc.begin(), loc.iter())), region.size());                 \
+        const auto region = result.unwrap();                                   \
+        BOOST_TEST(region.str() == expected);                                  \
+        BOOST_TEST(region.str().size() == expected.size());                    \
+        BOOST_TEST(static_cast<std::size_t>(std::distance(                     \
+                        loc.begin(), loc.iter())) == region.size());           \
     } else {                                                                   \
-    std::cerr << "lexer failed with input `";                                  \
-    std::cerr << token << "`. expected `" << expected << "`\n";                \
-    std::cerr << "reason: " << result.unwrap_err() << '\n';                    \
+        std::cerr << "lexer failed with input `";                              \
+        std::cerr << token << "`. expected `" << expected << "`\n";            \
+        std::cerr << "reason: " << result.unwrap_err() << '\n';                \
     }                                                                          \
 } while(false);                                                                \
 /**/
@@ -28,8 +28,9 @@ do {                                                                           \
 #define TOML11_TEST_LEX_REJECT(lxr, tkn)                                       \
 do {                                                                           \
     const std::string token   (tkn);                                           \
-    toml::detail::location<std::string> loc("test", token);                    \
+    toml::detail::location loc("test", token);                                 \
     const auto result = lxr::invoke(loc);                                      \
-    BOOST_CHECK(result.is_err());                                              \
-    BOOST_CHECK(loc.begin() == loc.iter());                                    \
+    BOOST_TEST(result.is_err());                                               \
+    const bool loc_same = (loc.begin() == loc.iter());                         \
+    BOOST_TEST(loc_same);                                                      \
 } while(false); /**/

tests/test_lex_floating.cpp

@@ -35,27 +35,35 @@ BOOST_AUTO_TEST_CASE(test_fractional_invalid)
 
 BOOST_AUTO_TEST_CASE(test_exponential_valid)
 {
-    TOML11_TEST_LEX_ACCEPT(lex_float, "1e10",       "1e10");      
-    TOML11_TEST_LEX_ACCEPT(lex_float, "1e+10",      "1e+10");     
-    TOML11_TEST_LEX_ACCEPT(lex_float, "1e-10",      "1e-10");     
-    TOML11_TEST_LEX_ACCEPT(lex_float, "+1e10",      "+1e10");     
-    TOML11_TEST_LEX_ACCEPT(lex_float, "+1e+10",     "+1e+10");    
-    TOML11_TEST_LEX_ACCEPT(lex_float, "+1e-10",     "+1e-10");    
-    TOML11_TEST_LEX_ACCEPT(lex_float, "-1e10",      "-1e10");     
-    TOML11_TEST_LEX_ACCEPT(lex_float, "-1e+10",     "-1e+10");    
-    TOML11_TEST_LEX_ACCEPT(lex_float, "-1e-10",     "-1e-10");    
-    TOML11_TEST_LEX_ACCEPT(lex_float, "123e-10",    "123e-10");   
-    TOML11_TEST_LEX_ACCEPT(lex_float, "1E10",       "1E10");      
-    TOML11_TEST_LEX_ACCEPT(lex_float, "1E+10",      "1E+10");     
-    TOML11_TEST_LEX_ACCEPT(lex_float, "1E-10",      "1E-10");     
-    TOML11_TEST_LEX_ACCEPT(lex_float, "123E-10",    "123E-10");   
-    TOML11_TEST_LEX_ACCEPT(lex_float, "1_2_3E-10",  "1_2_3E-10"); 
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1e10",       "1e10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1e+10",      "1e+10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1e-10",      "1e-10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "+1e10",      "+1e10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "+1e+10",     "+1e+10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "+1e-10",     "+1e-10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "-1e10",      "-1e10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "-1e+10",     "-1e+10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "-1e-10",     "-1e-10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "123e-10",    "123e-10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1E10",       "1E10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1E+10",      "1E+10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1E-10",      "1E-10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "123E-10",    "123E-10");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1_2_3E-10",  "1_2_3E-10");
     TOML11_TEST_LEX_ACCEPT(lex_float, "1_2_3E-1_0", "1_2_3E-1_0");
+
+#ifdef TOML11_USE_UNRELEASED_TOML_FEATURES
+    BOOST_TEST_MESSAGE("testing an unreleased toml feature: leading zeroes in float exponent part");
+    // toml-lang/toml master permits leading 0s in exp part (unreleased)
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1_2_3E-01",  "1_2_3E-01");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1_2_3E-0_1", "1_2_3E-0_1");
+#endif
 }
 
 BOOST_AUTO_TEST_CASE(test_exponential_invalid)
 {
-    TOML11_TEST_LEX_ACCEPT(lex_float, "1e1E0", "1e1"); 
+    // accept partially
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1e1E0", "1e1");
     TOML11_TEST_LEX_ACCEPT(lex_float, "1E1e0", "1E1");
 }
 
@@ -64,12 +72,26 @@ BOOST_AUTO_TEST_CASE(test_both_valid)
     TOML11_TEST_LEX_ACCEPT(lex_float, "6.02e23",          "6.02e23");
     TOML11_TEST_LEX_ACCEPT(lex_float, "6.02e+23",         "6.02e+23");
     TOML11_TEST_LEX_ACCEPT(lex_float, "1.112_650_06e-17", "1.112_650_06e-17");
+
+#ifdef TOML11_USE_UNRELEASED_TOML_FEATURES
+    BOOST_TEST_MESSAGE("testing an unreleased toml feature: leading zeroes in float exponent part");
+    // toml-lang/toml master permits leading 0s in exp part (unreleased)
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1.0e-07",          "1.0e-07");
+#endif
 }
 
 BOOST_AUTO_TEST_CASE(test_both_invalid)
 {
-    TOML11_TEST_LEX_ACCEPT(lex_float, "1e1.0",  "1e1");
     TOML11_TEST_LEX_REJECT(lex_float, "01e1.0");
+    // accept partially
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1e1.0",  "1e1");
+
+#ifdef TOML11_USE_UNRELEASED_TOML_FEATURES
+    BOOST_TEST_MESSAGE("testing an unreleased toml feature: leading zeroes in float exponent part");
+    // toml-lang/toml master permits leading 0s in exp part (unreleased)
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1.0e_01",  "1.0");
+    TOML11_TEST_LEX_ACCEPT(lex_float, "1.0e0__1", "1.0e0");
+#endif
 }
 
 BOOST_AUTO_TEST_CASE(test_special_floating_point)

tests/test_lex_key_comment.cpp

@@ -18,12 +18,11 @@ BOOST_AUTO_TEST_CASE(test_quoted_key)
 {
     TOML11_TEST_LEX_ACCEPT(lex_key, "\"127.0.0.1\"", "\"127.0.0.1\"");
     TOML11_TEST_LEX_ACCEPT(lex_key, "\"character encoding\"", "\"character encoding\"");
-#if defined(_MSC_VER) || defined(__INTEL_COMPILER)
+
+    // UTF-8 codepoint of characters that looks like "key" written upside down
     TOML11_TEST_LEX_ACCEPT(lex_key, "\"\xCA\x8E\xC7\x9D\xCA\x9E\"",
                                     "\"\xCA\x8E\xC7\x9D\xCA\x9E\"");
-#else
-    TOML11_TEST_LEX_ACCEPT(lex_key, u8"\"ʎǝʞ\"", u8"\"ʎǝʞ\"");
-#endif
+
     TOML11_TEST_LEX_ACCEPT(lex_key, "'key2'", "'key2'");
     TOML11_TEST_LEX_ACCEPT(lex_key, "'quoted \"value\"'", "'quoted \"value\"'");
 }

tests/test_lex_string.cpp

@@ -31,15 +31,9 @@ BOOST_AUTO_TEST_CASE(test_basic_string)
             "\"192.168.1.1\"",
             "\"192.168.1.1\"");
 
-#if defined(_MSC_VER) || defined(__INTEL_COMPILER)
     TOML11_TEST_LEX_ACCEPT(lex_string,
-            "\"\xE4\xB8\xAD\xE5\x9B\xBD\"",
-            "\"\xE4\xB8\xAD\xE5\x9B\xBD\"");
-#else
-    TOML11_TEST_LEX_ACCEPT(lex_string,
-            u8"\"中国\"",
-            u8"\"中国\"");
-#endif
+            "\"\xE4\xB8\xAD\xE5\x9B\xBD\"",  // UTF-8 string (means "China" in
+            "\"\xE4\xB8\xAD\xE5\x9B\xBD\""); // Chinese characters)
 
     TOML11_TEST_LEX_ACCEPT(lex_string,
             "\"You'll hate me after this - #\"",
@@ -57,6 +51,22 @@ BOOST_AUTO_TEST_CASE(test_ml_basic_string)
     TOML11_TEST_LEX_ACCEPT(lex_string,
         "\"\"\"\\\n  The quick brown \\\n\n  fox jumps over \\\n  the lazy dog.\\\n  \"\"\"",
         "\"\"\"\\\n  The quick brown \\\n\n  fox jumps over \\\n  the lazy dog.\\\n  \"\"\"");
+
+    TOML11_TEST_LEX_ACCEPT(lex_string,
+        "\"\"\"Here are two quotation marks: \"\". Simple enough.\"\"\"",
+        "\"\"\"Here are two quotation marks: \"\". Simple enough.\"\"\"");
+
+    TOML11_TEST_LEX_ACCEPT(lex_string,
+        "\"\"\"Here are three quotation marks: \"\"\\\".\"\"\"",
+        "\"\"\"Here are three quotation marks: \"\"\\\".\"\"\"");
+
+    TOML11_TEST_LEX_ACCEPT(lex_string,
+        "\"\"\"Here are fifteen quotation marks: \"\"\\\"\"\"\\\"\"\"\\\"\"\"\\\"\"\"\\\".\"\"\"",
+        "\"\"\"Here are fifteen quotation marks: \"\"\\\"\"\"\\\"\"\"\\\"\"\"\\\"\"\"\\\".\"\"\"");
+
+    TOML11_TEST_LEX_ACCEPT(lex_string,
+        "\"\"\"\"This,\" she said, \"is just a pointless statement.\"\"\"\"",
+        "\"\"\"\"This,\" she said, \"is just a pointless statement.\"\"\"\"");
 }
 
 BOOST_AUTO_TEST_CASE(test_literal_string)
@@ -83,4 +93,16 @@ BOOST_AUTO_TEST_CASE(test_ml_literal_string)
     TOML11_TEST_LEX_ACCEPT(lex_string,
         "'''\nThe first newline is\ntrimmed in raw strings.\n   All other whitespace\n   is preserved.\n'''",
         "'''\nThe first newline is\ntrimmed in raw strings.\n   All other whitespace\n   is preserved.\n'''");
+
+    TOML11_TEST_LEX_ACCEPT(lex_string,
+        "''''That's still pointless', she said.'''",
+        "''''That's still pointless', she said.'''");
+
+    TOML11_TEST_LEX_ACCEPT(lex_string,
+        "'''Here are fifteen quotation marks: \"\"\"\"\"\"\"\"\"\"\"\"\"\"\".'''",
+        "'''Here are fifteen quotation marks: \"\"\"\"\"\"\"\"\"\"\"\"\"\"\".'''");
+
+    TOML11_TEST_LEX_ACCEPT(lex_string,
+        "''''This,' she said, 'is just a pointless statement.''''",
+        "''''This,' she said, 'is just a pointless statement.''''");
 }

tests/test_literals.cpp

@@ -12,6 +12,170 @@ BOOST_AUTO_TEST_CASE(test_file_as_literal)
 {
     using namespace toml::literals::toml_literals;
 
+    {
+        const toml::value r{{"a", 42}, {"b", "baz"}};
+        const toml::value v = R"(
+            a = 42
+            b = "baz"
+        )"_toml;
+
+        BOOST_TEST(r == v);
+    }
+    {
+        const toml::value r{
+            {"c", 3.14},
+            {"table", toml::table{{"a", 42}, {"b", "baz"}}}
+        };
+        const toml::value v = R"(
+            c = 3.14
+            [table]
+            a = 42
+            b = "baz"
+        )"_toml;
+
+        BOOST_TEST(r == v);
+    }
+    {
+        const toml::value r{
+            {"table", toml::table{{"a", 42}, {"b", "baz"}}}
+        };
+        const toml::value v = R"(
+            [table]
+            a = 42
+            b = "baz"
+        )"_toml;
+
+        BOOST_TEST(r == v);
+    }
+    {
+        const toml::value r{
+            {"array_of_tables", toml::array{toml::table{}}}
+        };
+        const toml::value v = R"(
+            [[array_of_tables]]
+        )"_toml;
+
+        BOOST_TEST(r == v);
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_value_as_literal)
+{
+    using namespace toml::literals::toml_literals;
+
+    {
+        const toml::value v1 = "true"_toml;
+        const toml::value v2 = "false"_toml;
+
+        BOOST_TEST(v1.is_boolean());
+        BOOST_TEST(v2.is_boolean());
+        BOOST_TEST(toml::get<bool>(v1));
+        BOOST_TEST(!toml::get<bool>(v2));
+    }
+    {
+        const toml::value v1 = "123_456"_toml;
+        const toml::value v2 = "0b0010"_toml;
+        const toml::value v3 = "0xDEADBEEF"_toml;
+
+        BOOST_TEST(v1.is_integer());
+        BOOST_TEST(v2.is_integer());
+        BOOST_TEST(v3.is_integer());
+        BOOST_TEST(toml::get<toml::integer>(v1) == 123456);
+        BOOST_TEST(toml::get<toml::integer>(v2) == 2);
+        BOOST_TEST(toml::get<toml::integer>(v3) == 0xDEADBEEF);
+    }
+    {
+        const toml::value v1 = "3.1415"_toml;
+        const toml::value v2 = "6.02e+23"_toml;
+
+        BOOST_TEST(v1.is_floating());
+        BOOST_TEST(v2.is_floating());
+        BOOST_TEST(toml::get<double>(v1) == 3.1415,  boost::test_tools::tolerance(0.00001));
+        BOOST_TEST(toml::get<double>(v2) == 6.02e23, boost::test_tools::tolerance(0.0001));
+    }
+    {
+        const toml::value v1 = R"("foo")"_toml;
+        const toml::value v2 = R"('foo')"_toml;
+        const toml::value v3 = R"("""foo""")"_toml;
+        const toml::value v4 = R"('''foo''')"_toml;
+
+        BOOST_TEST(v1.is_string());
+        BOOST_TEST(v2.is_string());
+        BOOST_TEST(v3.is_string());
+        BOOST_TEST(v4.is_string());
+        BOOST_TEST(toml::get<std::string>(v1) == "foo");
+        BOOST_TEST(toml::get<std::string>(v2) == "foo");
+        BOOST_TEST(toml::get<std::string>(v3) == "foo");
+        BOOST_TEST(toml::get<std::string>(v4) == "foo");
+    }
+    {
+        {
+            const toml::value v1 = R"([1,2,3])"_toml;
+            BOOST_TEST(v1.is_array());
+            const bool result = (toml::get<std::vector<int>>(v1) == std::vector<int>{1,2,3});
+            BOOST_TEST(result);
+        }
+        {
+            const toml::value v2 = R"([1,])"_toml;
+            BOOST_TEST(v2.is_array());
+            const bool result = (toml::get<std::vector<int>>(v2) == std::vector<int>{1});
+            BOOST_TEST(result);
+        }
+        {
+            const toml::value v3 = R"([[1,]])"_toml;
+            BOOST_TEST(v3.is_array());
+            const bool result = (toml::get<std::vector<int>>(toml::get<toml::array>(v3).front()) == std::vector<int>{1});
+            BOOST_TEST(result);
+        }
+        {
+            const toml::value v4 = R"([[1],])"_toml;
+            BOOST_TEST(v4.is_array());
+            const bool result = (toml::get<std::vector<int>>(toml::get<toml::array>(v4).front()) == std::vector<int>{1});
+            BOOST_TEST(result);
+        }
+    }
+    {
+        const toml::value v1 = R"({a = 42})"_toml;
+
+        BOOST_TEST(v1.is_table());
+        const bool result = toml::get<std::map<std::string,int>>(v1) ==
+                               std::map<std::string,int>{{"a", 42}};
+        BOOST_TEST(result);
+    }
+    {
+        const toml::value v1 = "1979-05-27"_toml;
+
+        BOOST_TEST(v1.is_local_date());
+        BOOST_TEST(toml::get<toml::local_date>(v1) ==
+                   toml::local_date(1979, toml::month_t::May, 27));
+    }
+    {
+        const toml::value v1 = "12:00:00"_toml;
+
+        BOOST_TEST(v1.is_local_time());
+        const bool result = toml::get<std::chrono::hours>(v1) == std::chrono::hours(12);
+        BOOST_TEST(result);
+    }
+    {
+        const toml::value v1 = "1979-05-27T07:32:00"_toml;
+        BOOST_TEST(v1.is_local_datetime());
+        BOOST_TEST(toml::get<toml::local_datetime>(v1) ==
+            toml::local_datetime(toml::local_date(1979, toml::month_t::May, 27),
+                                 toml::local_time(7, 32, 0)));
+    }
+    {
+        const toml::value v1 = "1979-05-27T07:32:00Z"_toml;
+        BOOST_TEST(v1.is_offset_datetime());
+        BOOST_TEST(toml::get<toml::offset_datetime>(v1) ==
+            toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
+                                  toml::local_time(7, 32, 0), toml::time_offset(0, 0)));
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_file_as_u8_literal)
+{
+    using namespace toml::literals::toml_literals;
+
     {
         const toml::value r{{"a", 42}, {"b", "baz"}};
         const toml::value v = u8R"(
@@ -19,7 +183,7 @@ BOOST_AUTO_TEST_CASE(test_file_as_literal)
             b = "baz"
         )"_toml;
 
-        BOOST_CHECK_EQUAL(r, v);
+        BOOST_TEST(r == v);
     }
     {
         const toml::value r{
@@ -33,7 +197,7 @@ BOOST_AUTO_TEST_CASE(test_file_as_literal)
             b = "baz"
         )"_toml;
 
-        BOOST_CHECK_EQUAL(r, v);
+        BOOST_TEST(r == v);
     }
     {
         const toml::value r{
@@ -45,11 +209,21 @@ BOOST_AUTO_TEST_CASE(test_file_as_literal)
             b = "baz"
         )"_toml;
 
-        BOOST_CHECK_EQUAL(r, v);
+        BOOST_TEST(r == v);
+    }
+    {
+        const toml::value r{
+            {"array_of_tables", toml::array{toml::table{}}}
+        };
+        const toml::value v = u8R"(
+            [[array_of_tables]]
+        )"_toml;
+
+        BOOST_TEST(r == v);
     }
 }
 
-BOOST_AUTO_TEST_CASE(test_value_as_literal)
+BOOST_AUTO_TEST_CASE(test_value_as_u8_literal)
 {
     using namespace toml::literals::toml_literals;
 
@@ -57,97 +231,109 @@ BOOST_AUTO_TEST_CASE(test_value_as_literal)
         const toml::value v1 = u8"true"_toml;
         const toml::value v2 = u8"false"_toml;
 
-        BOOST_CHECK(v1.is_boolean());
-        BOOST_CHECK(v2.is_boolean());
-        BOOST_CHECK(toml::get<bool>(v1));
-        BOOST_CHECK(!toml::get<bool>(v2));
+        BOOST_TEST(v1.is_boolean());
+        BOOST_TEST(v2.is_boolean());
+        BOOST_TEST(toml::get<bool>(v1));
+        BOOST_TEST(!toml::get<bool>(v2));
     }
     {
         const toml::value v1 = u8"123_456"_toml;
         const toml::value v2 = u8"0b0010"_toml;
         const toml::value v3 = u8"0xDEADBEEF"_toml;
 
-        BOOST_CHECK(v1.is_integer());
-        BOOST_CHECK(v2.is_integer());
-        BOOST_CHECK(v3.is_integer());
-        BOOST_CHECK_EQUAL(toml::get<toml::integer>(v1), 123456);
-        BOOST_CHECK_EQUAL(toml::get<toml::integer>(v2), 2);
-        BOOST_CHECK_EQUAL(toml::get<toml::integer>(v3), 0xDEADBEEF);
+        BOOST_TEST(v1.is_integer());
+        BOOST_TEST(v2.is_integer());
+        BOOST_TEST(v3.is_integer());
+        BOOST_TEST(toml::get<toml::integer>(v1) == 123456);
+        BOOST_TEST(toml::get<toml::integer>(v2) == 2);
+        BOOST_TEST(toml::get<toml::integer>(v3) == 0xDEADBEEF);
     }
     {
         const toml::value v1 = u8"3.1415"_toml;
         const toml::value v2 = u8"6.02e+23"_toml;
 
-        BOOST_CHECK(v1.is_floating());
-        BOOST_CHECK(v2.is_floating());
-        BOOST_CHECK_CLOSE(toml::get<double>(v1), 3.1415,  0.00001);
-        BOOST_CHECK_CLOSE(toml::get<double>(v2), 6.02e23, 0.0001);
+        BOOST_TEST(v1.is_floating());
+        BOOST_TEST(v2.is_floating());
+        BOOST_TEST(toml::get<double>(v1) == 3.1415,  boost::test_tools::tolerance(0.00001));
+        BOOST_TEST(toml::get<double>(v2) == 6.02e23, boost::test_tools::tolerance(0.0001));
     }
     {
         const toml::value v1 = u8R"("foo")"_toml;
         const toml::value v2 = u8R"('foo')"_toml;
         const toml::value v3 = u8R"("""foo""")"_toml;
         const toml::value v4 = u8R"('''foo''')"_toml;
+        const toml::value v5 = u8R"("ひらがな")"_toml;
 
-        BOOST_CHECK(v1.is_string());
-        BOOST_CHECK(v2.is_string());
-        BOOST_CHECK(v3.is_string());
-        BOOST_CHECK(v4.is_string());
-        BOOST_CHECK_EQUAL(toml::get<std::string>(v1), "foo");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(v2), "foo");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(v3), "foo");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(v4), "foo");
+        BOOST_TEST(v1.is_string());
+        BOOST_TEST(v2.is_string());
+        BOOST_TEST(v3.is_string());
+        BOOST_TEST(v4.is_string());
+        BOOST_TEST(v5.is_string());
+        BOOST_TEST(toml::get<std::string>(v1) == "foo");
+        BOOST_TEST(toml::get<std::string>(v2) == "foo");
+        BOOST_TEST(toml::get<std::string>(v3) == "foo");
+        BOOST_TEST(toml::get<std::string>(v4) == "foo");
+        BOOST_TEST(toml::get<std::string>(v5) == "\xE3\x81\xB2\xE3\x82\x89\xE3\x81\x8C\xE3\x81\xAA");
     }
     {
-        const toml::value v1 = u8R"([1,2,3])"_toml;
-
-        BOOST_CHECK(v1.is_array());
-        BOOST_CHECK((toml::get<std::vector<int>>(v1) == std::vector<int>{1,2,3}));
-
-        const toml::value v2 = u8R"([1,])"_toml;
-
-        BOOST_CHECK(v2.is_array());
-        BOOST_CHECK((toml::get<std::vector<int>>(v2) == std::vector<int>{1}));
-
-        const toml::value v3 = u8R"([[1,]])"_toml;
-        BOOST_CHECK(v3.is_array());
-        BOOST_CHECK((toml::get<std::vector<int>>(toml::get<toml::array>(v3).front()) == std::vector<int>{1}));
-
-        const toml::value v4 = u8R"([[1],])"_toml;
-        BOOST_CHECK(v4.is_array());
-        BOOST_CHECK((toml::get<std::vector<int>>(toml::get<toml::array>(v4).front()) == std::vector<int>{1}));
+        {
+            const toml::value v1 = u8R"([1,2,3])"_toml;
+            BOOST_TEST(v1.is_array());
+            const bool result = (toml::get<std::vector<int>>(v1) == std::vector<int>{1,2,3});
+            BOOST_TEST(result);
+        }
+        {
+            const toml::value v2 = u8R"([1,])"_toml;
+            BOOST_TEST(v2.is_array());
+            const bool result = (toml::get<std::vector<int>>(v2) == std::vector<int>{1});
+            BOOST_TEST(result);
+        }
+        {
+            const toml::value v3 = u8R"([[1,]])"_toml;
+            BOOST_TEST(v3.is_array());
+            const bool result = (toml::get<std::vector<int>>(toml::get<toml::array>(v3).front()) == std::vector<int>{1});
+            BOOST_TEST(result);
+        }
+        {
+            const toml::value v4 = u8R"([[1],])"_toml;
+            BOOST_TEST(v4.is_array());
+            const bool result = (toml::get<std::vector<int>>(toml::get<toml::array>(v4).front()) == std::vector<int>{1});
+            BOOST_TEST(result);
+        }
     }
     {
         const toml::value v1 = u8R"({a = 42})"_toml;
 
-        BOOST_CHECK(v1.is_table());
-        BOOST_CHECK((toml::get<std::map<std::string,int>>(v1) ==
-                               std::map<std::string,int>{{"a", 42}}));
+        BOOST_TEST(v1.is_table());
+        const bool result = toml::get<std::map<std::string,int>>(v1) ==
+                               std::map<std::string,int>{{"a", 42}};
+        BOOST_TEST(result);
     }
     {
         const toml::value v1 = u8"1979-05-27"_toml;
 
-        BOOST_CHECK(v1.is_local_date());
-        BOOST_CHECK_EQUAL(toml::get<toml::local_date>(v1),
-                          toml::local_date(1979, toml::month_t::May, 27));
+        BOOST_TEST(v1.is_local_date());
+        BOOST_TEST(toml::get<toml::local_date>(v1) ==
+                   toml::local_date(1979, toml::month_t::May, 27));
     }
     {
         const toml::value v1 = u8"12:00:00"_toml;
 
-        BOOST_CHECK(v1.is_local_time());
-        BOOST_CHECK(toml::get<std::chrono::hours>(v1) == std::chrono::hours(12));
+        BOOST_TEST(v1.is_local_time());
+        const bool result = toml::get<std::chrono::hours>(v1) == std::chrono::hours(12);
+        BOOST_TEST(result);
     }
     {
         const toml::value v1 = u8"1979-05-27T07:32:00"_toml;
-        BOOST_CHECK(v1.is_local_datetime());
-        BOOST_CHECK_EQUAL(toml::get<toml::local_datetime>(v1),
+        BOOST_TEST(v1.is_local_datetime());
+        BOOST_TEST(toml::get<toml::local_datetime>(v1) ==
             toml::local_datetime(toml::local_date(1979, toml::month_t::May, 27),
                                  toml::local_time(7, 32, 0)));
     }
     {
-        const toml::value v1 = "1979-05-27T07:32:00Z"_toml;
-        BOOST_CHECK(v1.is_offset_datetime());
-        BOOST_CHECK_EQUAL(toml::get<toml::offset_datetime>(v1),
+        const toml::value v1 = u8"1979-05-27T07:32:00Z"_toml;
+        BOOST_TEST(v1.is_offset_datetime());
+        BOOST_TEST(toml::get<toml::offset_datetime>(v1) ==
             toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
                                   toml::local_time(7, 32, 0), toml::time_offset(0, 0)));
     }

tests/test_multiple_translation_unit_1.cpp

@@ -7,5 +7,5 @@ int main()
     const std::string content("a = 0");
     std::istringstream iss(content);
     const auto data = toml::parse(iss, "test_multiple_translation_unit.toml");
-    return read_a(data);
+    return read_a(toml::get<toml::table>(data));
 }

tests/test_parse_array.cpp

@@ -1,4 +1,4 @@
-#define BOOST_TEST_MODULE "parse_array_test"
+#define BOOST_TEST_MODULE "parse_array<toml::value>_test"
 #ifdef UNITTEST_FRAMEWORK_LIBRARY_EXIST
 #include <boost/test/unit_test.hpp>
 #else
@@ -13,118 +13,177 @@ using namespace detail;
 
 BOOST_AUTO_TEST_CASE(test_oneline_array)
 {
-    TOML11_TEST_PARSE_EQUAL(parse_array, "[]", array());
+    TOML11_TEST_PARSE_EQUAL(parse_array<toml::value>, "[]", array());
     {
         array a(5);
         a[0] = toml::value(3); a[1] = toml::value(1); a[2] = toml::value(4);
         a[3] = toml::value(1); a[4] = toml::value(5);
-        TOML11_TEST_PARSE_EQUAL(parse_array, "[3,1,4,1,5]", a);
+        TOML11_TEST_PARSE_EQUAL(parse_array<toml::value>, "[3,1,4,1,5]", a);
     }
     {
         array a(3);
         a[0] = toml::value("foo"); a[1] = toml::value("bar");
         a[2] = toml::value("baz");
-        TOML11_TEST_PARSE_EQUAL(parse_array, "[\"foo\", \"bar\",  \"baz\"]", a);
+        TOML11_TEST_PARSE_EQUAL(parse_array<toml::value>, "[\"foo\", \"bar\",  \"baz\"]", a);
     }
     {
         array a(5);
         a[0] = toml::value(3); a[1] = toml::value(1); a[2] = toml::value(4);
         a[3] = toml::value(1); a[4] = toml::value(5);
-        TOML11_TEST_PARSE_EQUAL(parse_array, "[3,1,4,1,5,]", a);
+        TOML11_TEST_PARSE_EQUAL(parse_array<toml::value>, "[3,1,4,1,5,]", a);
     }
     {
         array a(3);
         a[0] = toml::value("foo"); a[1] = toml::value("bar");
         a[2] = toml::value("baz");
-        TOML11_TEST_PARSE_EQUAL(parse_array, "[\"foo\", \"bar\",  \"baz\",]", a);
+        TOML11_TEST_PARSE_EQUAL(parse_array<toml::value>, "[\"foo\", \"bar\",  \"baz\",]", a);
     }
 }
 
 BOOST_AUTO_TEST_CASE(test_oneline_array_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "[]", toml::value(array()));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[]", toml::value(array()));
     {
         array a(5);
         a[0] = toml::value(3); a[1] = toml::value(1); a[2] = toml::value(4);
         a[3] = toml::value(1); a[4] = toml::value(5);
-        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "[3,1,4,1,5]", toml::value(a));
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[3,1,4,1,5]", toml::value(a));
     }
     {
         array a(3);
         a[0] = toml::value("foo"); a[1] = toml::value("bar");
         a[2] = toml::value("baz");
-        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "[\"foo\", \"bar\",  \"baz\"]", toml::value(a));
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[\"foo\", \"bar\",  \"baz\"]", toml::value(a));
     }
     {
         array a(5);
         a[0] = toml::value(3); a[1] = toml::value(1); a[2] = toml::value(4);
         a[3] = toml::value(1); a[4] = toml::value(5);
-        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "[3,1,4,1,5,]", toml::value(a));
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[3,1,4,1,5,]", toml::value(a));
     }
     {
         array a(3);
         a[0] = toml::value("foo"); a[1] = toml::value("bar");
         a[2] = toml::value("baz");
-        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "[\"foo\", \"bar\",  \"baz\",]", toml::value(a));
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[\"foo\", \"bar\",  \"baz\",]", toml::value(a));
     }
 }
 
 BOOST_AUTO_TEST_CASE(test_multiline_array)
 {
-    TOML11_TEST_PARSE_EQUAL(parse_array, "[\n#comment\n]", array());
+    TOML11_TEST_PARSE_EQUAL(parse_array<toml::value>, "[\n#comment\n]", array());
     {
         array a(5);
         a[0] = toml::value(3); a[1] = toml::value(1); a[2] = toml::value(4);
         a[3] = toml::value(1); a[4] = toml::value(5);
-        TOML11_TEST_PARSE_EQUAL(parse_array, "[3,\n1,\n4,\n1,\n5]", a);
+        TOML11_TEST_PARSE_EQUAL(parse_array<toml::value>, "[3,\n1,\n4,\n1,\n5]", a);
     }
     {
         array a(3);
         a[0] = toml::value("foo"); a[1] = toml::value("bar");
         a[2] = toml::value("baz");
-        TOML11_TEST_PARSE_EQUAL(parse_array, "[\"foo\",\n\"bar\",\n\"baz\"]", a);
+        TOML11_TEST_PARSE_EQUAL(parse_array<toml::value>, "[\"foo\",\n\"bar\",\n\"baz\"]", a);
     }
 
     {
         array a(5);
         a[0] = toml::value(3); a[1] = toml::value(1); a[2] = toml::value(4);
         a[3] = toml::value(1); a[4] = toml::value(5);
-        TOML11_TEST_PARSE_EQUAL(parse_array, "[3,#comment\n1,#comment\n4,#comment\n1,#comment\n5]", a);
+        TOML11_TEST_PARSE_EQUAL(parse_array<toml::value>, "[3,#comment\n1,#comment\n4,#comment\n1,#comment\n5]", a);
     }
     {
         array a(3);
         a[0] = toml::value("foo"); a[1] = toml::value("b#r");
         a[2] = toml::value("b#z");
-        TOML11_TEST_PARSE_EQUAL(parse_array, "[\"foo\",#comment\n\"b#r\",#comment\n\"b#z\"#comment\n]", a);
+        TOML11_TEST_PARSE_EQUAL(parse_array<toml::value>, "[\"foo\",#comment\n\"b#r\",#comment\n\"b#z\"#comment\n]", a);
     }
 }
 
 BOOST_AUTO_TEST_CASE(test_multiline_array_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "[\n#comment\n]", toml::value(array()));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[\n#comment\n]", toml::value(array()));
     {
         array a(5);
         a[0] = toml::value(3); a[1] = toml::value(1); a[2] = toml::value(4);
         a[3] = toml::value(1); a[4] = toml::value(5);
-        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "[3,\n1,\n4,\n1,\n5]", toml::value(a));
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[3,\n1,\n4,\n1,\n5]", toml::value(a));
     }
     {
         array a(3);
         a[0] = toml::value("foo"); a[1] = toml::value("bar");
         a[2] = toml::value("baz");
-        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "[\"foo\",\n\"bar\",\n\"baz\"]", toml::value(a));
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[\"foo\",\n\"bar\",\n\"baz\"]", toml::value(a));
     }
 
     {
         array a(5);
         a[0] = toml::value(3); a[1] = toml::value(1); a[2] = toml::value(4);
         a[3] = toml::value(1); a[4] = toml::value(5);
-        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "[3,#comment\n1,#comment\n4,#comment\n1,#comment\n5]", toml::value(a));
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[3,#comment\n1,#comment\n4,#comment\n1,#comment\n5]", toml::value(a));
     }
     {
         array a(3);
         a[0] = toml::value("foo"); a[1] = toml::value("b#r");
         a[2] = toml::value("b#z");
-        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "[\"foo\",#comment\n\"b#r\",#comment\n\"b#z\"#comment\n]", toml::value(a));
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[\"foo\",#comment\n\"b#r\",#comment\n\"b#z\"#comment\n]", toml::value(a));
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_heterogeneous_array)
+{
+#ifndef TOML11_USE_UNRELEASED_TOML_FEATURES
+    BOOST_TEST_MESSAGE("In strict TOML v0.5.0, heterogeneous arrays are not allowed.");
+#else
+    {
+        array a(5);
+        a[0] = toml::value("foo");
+        a[1] = toml::value(3.14);
+        a[2] = toml::value(42);
+        a[3] = toml::value{toml::value("array"), toml::value("of"), toml::value("hetero-array"), toml::value(1)};
+        a[4] = toml::value{{"key", "value"}};
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[\"foo\", 3.14, 42, [\"array\", \"of\", \"hetero-array\", 1], {key = \"value\"}]", toml::value(a));
+    }
+    {
+        array a(5);
+        a[0] = toml::value("foo");
+        a[1] = toml::value(3.14);
+        a[2] = toml::value(42);
+        a[3] = toml::value{toml::value("array"), toml::value("of"), toml::value("hetero-array"), toml::value(1)};
+        a[4] = toml::value{{"key", "value"}};
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[\"foo\",\n 3.14,\n 42,\n [\"array\", \"of\", \"hetero-array\", 1],\n {key = \"value\"},\n]", toml::value(a));
+    }
+    {
+        array a(5);
+        a[0] = toml::value("foo");
+        a[1] = toml::value(3.14);
+        a[2] = toml::value(42);
+        a[3] = toml::value{toml::value("array"), toml::value("of"), toml::value("hetero-array"), toml::value(1)};
+        a[4] = toml::value{{"key", "value"}};
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[\"foo\",#comment\n 3.14,#comment\n 42,#comment\n [\"array\", \"of\", \"hetero-array\", 1],#comment\n {key = \"value\"},#comment\n]#comment", toml::value(a));
+    }
+    {
+        array a(5);
+        a[0] = toml::value("foo");
+        a[1] = toml::value(3.14);
+        a[2] = toml::value(42);
+        a[3] = toml::value{toml::value("array"), toml::value("of"), toml::value("hetero-array"), toml::value(1)};
+        a[4] = toml::value{{"key", "value"}};
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "[\"foo\",\n 3.14,\n 42,\n [\"array\",\n \"of\",\n \"hetero-array\",\n 1],\n {key = \"value\"},\n]", toml::value(a));
+    }
+#endif
+}
+
+BOOST_AUTO_TEST_CASE(test_comments_after_comma)
+{
+    {
+        array a;
+        a.push_back("foo");
+        a.push_back("bar");
+        a.push_back("baz");
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
+            "[ \"foo\" # comment\n"
+            ", \"bar\" # comment\n"
+            ", \"baz\" # comment\n"
+            "]", toml::value(a));
     }
 }

tests/test_parse_aux.hpp

@@ -1,22 +1,21 @@
 #include <iostream>
 #include <iomanip>
 #include <algorithm>
-#include <toml/region.hpp>
-#include <toml/result.hpp>
+#include <toml.hpp>
 
 // some of the parsers returns not only a value but also a region.
 #define TOML11_TEST_PARSE_EQUAL(psr, tkn, expct)                               \
 do {                                                                           \
     const std::string token(tkn);                                              \
-    toml::detail::location<std::string> loc("test", token);                    \
+    toml::detail::location loc("test", token);                                 \
     const auto result = psr(loc);                                              \
-    BOOST_CHECK(result.is_ok());                                               \
+    BOOST_TEST(result.is_ok());                                                \
     if(result.is_ok()){                                                        \
-    BOOST_CHECK(result.unwrap().first == expct);                               \
+        BOOST_TEST(result.unwrap().first == expct);                            \
     } else {                                                                   \
-    std::cerr << "parser " << #psr << " failed with input `";                  \
-    std::cerr << token << "`.\n";                                              \
-    std::cerr << "reason: " << result.unwrap_err() << '\n';                    \
+        std::cerr << "parser " << #psr << " failed with input `";              \
+        std::cerr << token << "`.\n";                                          \
+        std::cerr << "reason: " << result.unwrap_err() << '\n';                \
     }                                                                          \
 } while(false);                                                                \
 /**/
@@ -24,15 +23,15 @@ do {                                                                           \
 #define TOML11_TEST_PARSE_EQUAL_VALUE(psr, tkn, expct)                         \
 do {                                                                           \
     const std::string token(tkn);                                              \
-    toml::detail::location<std::string> loc("test", token);                    \
+    toml::detail::location loc("test", token);                                 \
     const auto result = psr(loc);                                              \
-    BOOST_CHECK(result.is_ok());                                               \
+    BOOST_TEST(result.is_ok());                                                \
     if(result.is_ok()){                                                        \
-    BOOST_CHECK(result.unwrap() == expct);                                     \
+        BOOST_TEST(result.unwrap() == expct);                                  \
     } else {                                                                   \
-    std::cerr << "parse_value failed with input `";                            \
-    std::cerr << token << "`.\n";                                              \
-    std::cerr << "reason: " << result.unwrap_err() << '\n';                    \
+        std::cerr << "parse_value failed with input `";                        \
+        std::cerr << token << "`.\n";                                          \
+        std::cerr << "reason: " << result.unwrap_err() << '\n';                \
     }                                                                          \
 } while(false);                                                                \
 /**/

tests/test_parse_boolean.cpp

@@ -19,6 +19,6 @@ BOOST_AUTO_TEST_CASE(test_boolean)
 
 BOOST_AUTO_TEST_CASE(test_boolean_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value,  "true", toml::value( true));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "false", toml::value(false));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,  "true", toml::value( true));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "false", toml::value(false));
 }

tests/test_parse_datetime.cpp

@@ -21,10 +21,10 @@ BOOST_AUTO_TEST_CASE(test_time)
 
 BOOST_AUTO_TEST_CASE(test_time_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "07:32:00",        toml::value(toml::local_time(7, 32, 0)));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "07:32:00.99",     toml::value(toml::local_time(7, 32, 0, 990, 0)));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "07:32:00.999",    toml::value(toml::local_time(7, 32, 0, 999, 0)));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "07:32:00.999999", toml::value(toml::local_time(7, 32, 0, 999, 999)));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "07:32:00",        toml::value(toml::local_time(7, 32, 0)));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "07:32:00.99",     toml::value(toml::local_time(7, 32, 0, 990, 0)));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "07:32:00.999",    toml::value(toml::local_time(7, 32, 0, 999, 0)));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "07:32:00.999999", toml::value(toml::local_time(7, 32, 0, 999, 999)));
 }
 
 BOOST_AUTO_TEST_CASE(test_date)
@@ -34,7 +34,7 @@ BOOST_AUTO_TEST_CASE(test_date)
 }
 BOOST_AUTO_TEST_CASE(test_date_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27",
                             value(toml::local_date(1979, toml::month_t::May, 27)));
 }
 
@@ -64,25 +64,25 @@ BOOST_AUTO_TEST_CASE(test_datetime)
 
 BOOST_AUTO_TEST_CASE(test_datetime_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27T07:32:00",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27T07:32:00",
         toml::value(toml::local_datetime(toml::local_date(1979, toml::month_t::May, 27), toml::local_time(7, 32, 0))));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27T07:32:00.99",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27T07:32:00.99",
         toml::value(toml::local_datetime(toml::local_date(1979, toml::month_t::May, 27), toml::local_time(7, 32, 0, 990, 0))));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27T07:32:00.999999",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27T07:32:00.999999",
         toml::value(toml::local_datetime(toml::local_date(1979, toml::month_t::May, 27), toml::local_time(7, 32, 0, 999, 999))));
 
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27t07:32:00",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27t07:32:00",
         toml::value(toml::local_datetime(toml::local_date(1979, toml::month_t::May, 27), toml::local_time(7, 32, 0))));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27t07:32:00.99",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27t07:32:00.99",
         toml::value(toml::local_datetime(toml::local_date(1979, toml::month_t::May, 27), toml::local_time(7, 32, 0, 990, 0))));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27t07:32:00.999999",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27t07:32:00.999999",
         toml::value(toml::local_datetime(toml::local_date(1979, toml::month_t::May, 27), toml::local_time(7, 32, 0, 999, 999))));
 
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27 07:32:00",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27 07:32:00",
         toml::value(toml::local_datetime(toml::local_date(1979, toml::month_t::May, 27), toml::local_time(7, 32, 0))));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27 07:32:00.99",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27 07:32:00.99",
         toml::value(toml::local_datetime(toml::local_date(1979, toml::month_t::May, 27), toml::local_time(7, 32, 0, 990, 0))));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27 07:32:00.999999",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27 07:32:00.999999",
         toml::value(toml::local_datetime(toml::local_date(1979, toml::month_t::May, 27), toml::local_time(7, 32, 0, 999, 999))));
 }
 
@@ -111,23 +111,23 @@ BOOST_AUTO_TEST_CASE(test_offset_datetime)
 
 BOOST_AUTO_TEST_CASE(test_offset_datetime_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27T07:32:00Z",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27T07:32:00Z",
         toml::value(toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
                               toml::local_time(7, 32, 0), toml::time_offset(0, 0))));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27T07:32:00.99Z",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27T07:32:00.99Z",
         toml::value(toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
                               toml::local_time(7, 32, 0, 990, 0), toml::time_offset(0, 0))));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27T07:32:00.999999Z",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27T07:32:00.999999Z",
         toml::value(toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
                               toml::local_time(7, 32, 0, 999, 999), toml::time_offset(0, 0))));
 
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27T07:32:00+09:00",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27T07:32:00+09:00",
         toml::value(toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
                               toml::local_time(7, 32, 0), toml::time_offset(9, 0))));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27T07:32:00.99+09:00",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27T07:32:00.99+09:00",
         toml::value(toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
                               toml::local_time(7, 32, 0, 990, 0), toml::time_offset(9, 0))));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1979-05-27T07:32:00.999999+09:00",
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1979-05-27T07:32:00.999999+09:00",
         toml::value(toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
                               toml::local_time(7, 32, 0, 999, 999), toml::time_offset(9, 0))));
 }

tests/test_parse_file.cpp

@@ -8,192 +8,385 @@
 #include <toml.hpp>
 #include <iostream>
 #include <fstream>
-
+#include <map>
+#include <deque>
 
 BOOST_AUTO_TEST_CASE(test_example)
 {
     const auto data = toml::parse("toml/tests/example.toml");
 
-    BOOST_CHECK_EQUAL(toml::get<std::string>(data.at("title")), "TOML Example");
-    toml::Table owner = toml::get<toml::Table>(data.at("owner"));
+    BOOST_TEST(toml::find<std::string>(data, "title") == "TOML Example");
+    const auto& owner = toml::find(data, "owner");
     {
-        BOOST_CHECK_EQUAL(toml::get<std::string>(owner.at("name")), "Tom Preston-Werner");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(owner.at("organization")), "GitHub");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(owner.at("bio")),
+        BOOST_TEST(toml::find<std::string>(owner, "name") == "Tom Preston-Werner");
+        BOOST_TEST(toml::find<std::string>(owner, "organization") == "GitHub");
+        BOOST_TEST(toml::find<std::string>(owner, "bio") ==
                           "GitHub Cofounder & CEO\nLikes tater tots and beer.");
-        BOOST_CHECK_EQUAL(toml::get<toml::Datetime>(owner.at("dob")),
+        BOOST_TEST(toml::find<toml::offset_datetime>(owner, "dob") ==
                           toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
                                                 toml::local_time(7, 32, 0), toml::time_offset(0, 0)));
     }
 
-    toml::Table database = toml::get<toml::Table>(data.at("database"));
+    const auto& database = toml::find(data, "database");
     {
-        BOOST_CHECK_EQUAL(toml::get<std::string>(database.at("server")), "192.168.1.1");
+        BOOST_TEST(toml::find<std::string>(database, "server") == "192.168.1.1");
         const std::vector<int> expected_ports{8001, 8001, 8002};
-        BOOST_CHECK(toml::get<std::vector<int>>(database.at("ports")) == expected_ports);
-        BOOST_CHECK_EQUAL(toml::get<int>(database.at("connection_max")), 5000);
-        BOOST_CHECK_EQUAL(toml::get<bool>(database.at("enabled")), true);
+        BOOST_CHECK(toml::find<std::vector<int>>(database, "ports") == expected_ports);
+        BOOST_TEST(toml::find<int >(database, "connection_max") == 5000);
+        BOOST_TEST(toml::find<bool>(database, "enabled") == true);
     }
 
-    toml::Table servers = toml::get<toml::Table>(data.at("servers"));
+    const auto& servers = toml::find(data, "servers");
     {
-        toml::Table alpha = toml::get<toml::Table>(servers.at("alpha"));
-        BOOST_CHECK_EQUAL(toml::get<std::string>(alpha.at("ip")), "10.0.0.1");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(alpha.at("dc")), "eqdc10");
+        toml::table alpha = toml::find<toml::table>(servers, "alpha");
+        BOOST_TEST(toml::get<std::string>(alpha.at("ip")) == "10.0.0.1");
+        BOOST_TEST(toml::get<std::string>(alpha.at("dc")) == "eqdc10");
 
-        toml::Table beta = toml::get<toml::Table>(servers.at("beta"));
-        BOOST_CHECK_EQUAL(toml::get<std::string>(beta.at("ip")), "10.0.0.2");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(beta.at("dc")), "eqdc10");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(beta.at("country")), "\xE4\xB8\xAD\xE5\x9B\xBD");
+        toml::table beta = toml::find<toml::table>(servers, "beta");
+        BOOST_TEST(toml::get<std::string>(beta.at("ip")) == "10.0.0.2");
+        BOOST_TEST(toml::get<std::string>(beta.at("dc")) == "eqdc10");
+        BOOST_TEST(toml::get<std::string>(beta.at("country")) == "\xE4\xB8\xAD\xE5\x9B\xBD");
     }
 
-    toml::Table clients = toml::get<toml::Table>(data.at("clients"));
+    const auto& clients = toml::find(data, "clients");
     {
-        toml::Array clients_data = toml::get<toml::Array>(clients.at("data"));
+        toml::array clients_data = toml::find<toml::array>(clients, "data");
+
         std::vector<std::string> expected_name{"gamma", "delta"};
-        BOOST_CHECK(toml::get<std::vector<std::string>>(clients_data.at(0)) ==
-                    expected_name);
+        BOOST_CHECK(toml::get<std::vector<std::string>>(clients_data.at(0)) == expected_name);
+
         std::vector<int> expected_number{1, 2};
-        BOOST_CHECK(toml::get<std::vector<int>>(clients_data.at(1)) ==
-                    expected_number);
+        BOOST_CHECK(toml::get<std::vector<int>>(clients_data.at(1)) == expected_number);
+
         std::vector<std::string> expected_hosts{"alpha", "omega"};
-        BOOST_CHECK(toml::get<std::vector<std::string>>(clients.at("hosts")) ==
-                    expected_hosts);
+        BOOST_CHECK(toml::find<std::vector<std::string>>(clients, "hosts") == expected_hosts);
     }
 
-    std::vector<toml::Table> products =
-        toml::get<std::vector<toml::Table>>(data.at("products"));
+    std::vector<toml::table> products =
+        toml::find<std::vector<toml::table>>(data, "products");
     {
-        BOOST_CHECK_EQUAL(toml::get<std::string>(products.at(0).at("name")),
-                          "Hammer");
-        BOOST_CHECK_EQUAL(toml::get<std::int64_t>(products.at(0).at("sku")),
-                          738594937);
+        BOOST_TEST(toml::get<std::string>(products.at(0).at("name")) == "Hammer");
+        BOOST_TEST(toml::get<std::int64_t>(products.at(0).at("sku")) == 738594937);
 
-        BOOST_CHECK_EQUAL(toml::get<std::string>(products.at(1).at("name")),
-                          "Nail");
-        BOOST_CHECK_EQUAL(toml::get<std::int64_t>(products.at(1).at("sku")),
-                          284758393);
-        BOOST_CHECK_EQUAL(toml::get<std::string>(products.at(1).at("color")),
-                          "gray");
+        BOOST_TEST(toml::get<std::string>(products.at(1).at("name")) == "Nail");
+        BOOST_TEST(toml::get<std::int64_t>(products.at(1).at("sku")) == 284758393);
+        BOOST_TEST(toml::get<std::string>(products.at(1).at("color")) == "gray");
     }
 }
 
 BOOST_AUTO_TEST_CASE(test_example_stream)
 {
-    std::ifstream ifs("toml/tests/example.toml");
+    std::ifstream ifs("toml/tests/example.toml", std::ios::binary);
     const auto data = toml::parse(ifs);
 
-    BOOST_CHECK_EQUAL(toml::get<std::string>(data.at("title")), "TOML Example");
-    toml::Table owner = toml::get<toml::Table>(data.at("owner"));
+    BOOST_TEST(toml::find<std::string>(data, "title") == "TOML Example");
+    const auto& owner = toml::find(data, "owner");
     {
-        BOOST_CHECK_EQUAL(toml::get<std::string>(owner.at("name")), "Tom Preston-Werner");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(owner.at("organization")), "GitHub");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(owner.at("bio")),
+        BOOST_TEST(toml::find<std::string>(owner, "name") == "Tom Preston-Werner");
+        BOOST_TEST(toml::find<std::string>(owner, "organization") == "GitHub");
+        BOOST_TEST(toml::find<std::string>(owner, "bio") ==
                           "GitHub Cofounder & CEO\nLikes tater tots and beer.");
-        BOOST_CHECK_EQUAL(toml::get<toml::Datetime>(owner.at("dob")),
+        BOOST_TEST(toml::find<toml::offset_datetime>(owner, "dob") ==
                           toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
                                                 toml::local_time(7, 32, 0), toml::time_offset(0, 0)));
     }
 
-    toml::Table database = toml::get<toml::Table>(data.at("database"));
+    const auto& database = toml::find(data, "database");
     {
-        BOOST_CHECK_EQUAL(toml::get<std::string>(database.at("server")), "192.168.1.1");
+        BOOST_TEST(toml::find<std::string>(database, "server") == "192.168.1.1");
         const std::vector<int> expected_ports{8001, 8001, 8002};
-        BOOST_CHECK(toml::get<std::vector<int>>(database.at("ports")) == expected_ports);
-        BOOST_CHECK_EQUAL(toml::get<int>(database.at("connection_max")), 5000);
-        BOOST_CHECK_EQUAL(toml::get<bool>(database.at("enabled")), true);
+        BOOST_CHECK(toml::find<std::vector<int>>(database, "ports") == expected_ports);
+        BOOST_TEST(toml::find<int >(database, "connection_max") == 5000);
+        BOOST_TEST(toml::find<bool>(database, "enabled") == true);
     }
 
-    toml::Table servers = toml::get<toml::Table>(data.at("servers"));
+    const auto& servers = toml::find(data, "servers");
     {
-        toml::Table alpha = toml::get<toml::Table>(servers.at("alpha"));
-        BOOST_CHECK_EQUAL(toml::get<std::string>(alpha.at("ip")), "10.0.0.1");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(alpha.at("dc")), "eqdc10");
+        toml::table alpha = toml::find<toml::table>(servers, "alpha");
+        BOOST_TEST(toml::get<std::string>(alpha.at("ip")) == "10.0.0.1");
+        BOOST_TEST(toml::get<std::string>(alpha.at("dc")) == "eqdc10");
 
-        toml::Table beta = toml::get<toml::Table>(servers.at("beta"));
-        BOOST_CHECK_EQUAL(toml::get<std::string>(beta.at("ip")), "10.0.0.2");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(beta.at("dc")), "eqdc10");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(beta.at("country")), "\xE4\xB8\xAD\xE5\x9B\xBD");
+        toml::table beta = toml::find<toml::table>(servers, "beta");
+        BOOST_TEST(toml::get<std::string>(beta.at("ip")) == "10.0.0.2");
+        BOOST_TEST(toml::get<std::string>(beta.at("dc")) == "eqdc10");
+        BOOST_TEST(toml::get<std::string>(beta.at("country")) == "\xE4\xB8\xAD\xE5\x9B\xBD");
     }
 
-    toml::Table clients = toml::get<toml::Table>(data.at("clients"));
+    const auto& clients = toml::find(data, "clients");
     {
-        toml::Array clients_data = toml::get<toml::Array>(clients.at("data"));
+        toml::array clients_data = toml::find<toml::array>(clients, "data");
         std::vector<std::string> expected_name{"gamma", "delta"};
-        BOOST_CHECK(toml::get<std::vector<std::string>>(clients_data.at(0)) ==
-                    expected_name);
+        BOOST_CHECK(toml::get<std::vector<std::string>>(clients_data.at(0)) == expected_name);
+
         std::vector<int> expected_number{1, 2};
-        BOOST_CHECK(toml::get<std::vector<int>>(clients_data.at(1)) ==
-                    expected_number);
+        BOOST_CHECK(toml::get<std::vector<int>>(clients_data.at(1)) == expected_number);
+
         std::vector<std::string> expected_hosts{"alpha", "omega"};
-        BOOST_CHECK(toml::get<std::vector<std::string>>(clients.at("hosts")) ==
-                    expected_hosts);
+        BOOST_CHECK(toml::find<std::vector<std::string>>(clients, "hosts") == expected_hosts);
     }
 
-    std::vector<toml::Table> products =
-        toml::get<std::vector<toml::Table>>(data.at("products"));
+    std::vector<toml::table> products =
+        toml::find<std::vector<toml::table>>(data, "products");
     {
-        BOOST_CHECK_EQUAL(toml::get<std::string>(products.at(0).at("name")),
+        BOOST_TEST(toml::get<std::string>(products.at(0).at("name")) ==
                           "Hammer");
-        BOOST_CHECK_EQUAL(toml::get<std::int64_t>(products.at(0).at("sku")),
+        BOOST_TEST(toml::get<std::int64_t>(products.at(0).at("sku")) ==
                           738594937);
 
-        BOOST_CHECK_EQUAL(toml::get<std::string>(products.at(1).at("name")),
+        BOOST_TEST(toml::get<std::string>(products.at(1).at("name")) ==
                           "Nail");
-        BOOST_CHECK_EQUAL(toml::get<std::int64_t>(products.at(1).at("sku")),
+        BOOST_TEST(toml::get<std::int64_t>(products.at(1).at("sku")) ==
                           284758393);
-        BOOST_CHECK_EQUAL(toml::get<std::string>(products.at(1).at("color")),
+        BOOST_TEST(toml::get<std::string>(products.at(1).at("color")) ==
                           "gray");
     }
 }
 
-
 BOOST_AUTO_TEST_CASE(test_fruit)
 {
     const auto data = toml::parse("toml/tests/fruit.toml");
-    const auto blah = toml::get<std::vector<toml::Table>>(
-                      toml::get<toml::Table>(data.at("fruit")).at("blah"));
-    BOOST_CHECK_EQUAL(toml::get<std::string>(blah.at(0).at("name")), "apple");
-    BOOST_CHECK_EQUAL(toml::get<std::string>(blah.at(1).at("name")), "banana");
+    const auto blah = toml::find<toml::array>(toml::find(data, "fruit"), "blah");
+    BOOST_TEST(toml::find<std::string>(blah.at(0), "name") == "apple");
+    BOOST_TEST(toml::find<std::string>(blah.at(1), "name") == "banana");
     {
-        const auto physical = toml::get<toml::Table>(blah.at(0).at("physical"));
-        BOOST_CHECK_EQUAL(toml::get<std::string>(physical.at("color")), "red");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(physical.at("shape")), "round");
+        const auto physical = toml::find(blah.at(0), "physical");
+        BOOST_TEST(toml::find<std::string>(physical, "color") == "red");
+        BOOST_TEST(toml::find<std::string>(physical, "shape") == "round");
     }
     {
-        const auto physical = toml::get<toml::Table>(blah.at(1).at("physical"));
-        BOOST_CHECK_EQUAL(toml::get<std::string>(physical.at("color")), "yellow");
-        BOOST_CHECK_EQUAL(toml::get<std::string>(physical.at("shape")), "bent");
+        const auto physical = toml::find(blah.at(1), "physical");
+        BOOST_TEST(toml::find<std::string>(physical, "color") == "yellow");
+        BOOST_TEST(toml::find<std::string>(physical, "shape") == "bent");
     }
 }
 
 BOOST_AUTO_TEST_CASE(test_hard_example)
 {
     const auto data = toml::parse("toml/tests/hard_example.toml");
-    const auto the = toml::get<toml::Table>(data.at("the"));
-    BOOST_CHECK_EQUAL(toml::get<std::string>(the.at("test_string")),
+    const auto the = toml::find(data, "the");
+    BOOST_TEST(toml::find<std::string>(the, "test_string") ==
                       "You'll hate me after this - #");
 
-    const auto hard = toml::get<toml::Table>(the.at("hard"));
+    const auto hard = toml::find(the, "hard");
     const std::vector<std::string> expected_the_hard_test_array{"] ", " # "};
-    BOOST_CHECK(toml::get<std::vector<std::string>>(hard.at("test_array")) ==
+    BOOST_CHECK(toml::find<std::vector<std::string>>(hard, "test_array") ==
                 expected_the_hard_test_array);
     const std::vector<std::string> expected_the_hard_test_array2{
         "Test #11 ]proved that", "Experiment #9 was a success"};
-    BOOST_CHECK(toml::get<std::vector<std::string>>(hard.at("test_array2")) ==
+    BOOST_CHECK(toml::find<std::vector<std::string>>(hard, "test_array2") ==
                 expected_the_hard_test_array2);
-    BOOST_CHECK_EQUAL(toml::get<std::string>(hard.at("another_test_string")),
+    BOOST_TEST(toml::find<std::string>(hard, "another_test_string") ==
                       " Same thing, but with a string #");
-    BOOST_CHECK_EQUAL(toml::get<std::string>(hard.at("harder_test_string")),
+    BOOST_TEST(toml::find<std::string>(hard, "harder_test_string") ==
                       " And when \"'s are in the string, along with # \"");
 
-    const auto bit = toml::get<toml::Table>(hard.at("bit#"));
-    BOOST_CHECK_EQUAL(toml::get<std::string>(bit.at("what?")),
+    const auto bit = toml::find(hard, "bit#");
+    BOOST_TEST(toml::find<std::string>(bit, "what?") ==
                       "You don't think some user won't do that?");
     const std::vector<std::string> expected_multi_line_array{"]"};
-    BOOST_CHECK(toml::get<std::vector<std::string>>(bit.at("multi_line_array")) ==
+    BOOST_CHECK(toml::find<std::vector<std::string>>(bit, "multi_line_array") ==
                 expected_multi_line_array);
 }
+BOOST_AUTO_TEST_CASE(test_hard_example_comment)
+{
+    const auto data = toml::parse<toml::preserve_comments>("toml/tests/hard_example.toml");
+    const auto the = toml::find(data, "the");
+    BOOST_TEST(toml::find<std::string>(the, "test_string") ==
+                      "You'll hate me after this - #");
+
+    const auto hard = toml::find(the, "hard");
+    const std::vector<std::string> expected_the_hard_test_array{"] ", " # "};
+    BOOST_CHECK(toml::find<std::vector<std::string>>(hard, "test_array") ==
+                expected_the_hard_test_array);
+    const std::vector<std::string> expected_the_hard_test_array2{
+        "Test #11 ]proved that", "Experiment #9 was a success"};
+    BOOST_CHECK(toml::find<std::vector<std::string>>(hard, "test_array2") ==
+                expected_the_hard_test_array2);
+    BOOST_TEST(toml::find<std::string>(hard, "another_test_string") ==
+                      " Same thing, but with a string #");
+    BOOST_TEST(toml::find<std::string>(hard, "harder_test_string") ==
+                      " And when \"'s are in the string, along with # \"");
+
+    const auto bit = toml::find(hard, "bit#");
+    BOOST_TEST(toml::find<std::string>(bit, "what?") ==
+                      "You don't think some user won't do that?");
+    const std::vector<std::string> expected_multi_line_array{"]"};
+    BOOST_CHECK(toml::find<std::vector<std::string>>(bit, "multi_line_array") ==
+                expected_multi_line_array);
+}
+
+
+BOOST_AUTO_TEST_CASE(test_example_preserve_comment)
+{
+    const auto data = toml::parse<toml::preserve_comments>("toml/tests/example.toml");
+
+    BOOST_TEST(toml::find<std::string>(data, "title") == "TOML Example");
+    const auto& owner = toml::find(data, "owner");
+    {
+        BOOST_TEST(toml::find<std::string>(owner, "name") == "Tom Preston-Werner");
+        BOOST_TEST(toml::find<std::string>(owner, "organization") == "GitHub");
+        BOOST_TEST(toml::find<std::string>(owner, "bio") ==
+                          "GitHub Cofounder & CEO\nLikes tater tots and beer.");
+        BOOST_TEST(toml::find<toml::offset_datetime>(owner, "dob") ==
+                          toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
+                                                toml::local_time(7, 32, 0), toml::time_offset(0, 0)));
+        BOOST_TEST(toml::find(owner, "dob").comments().at(0) ==
+                          " First class dates? Why not?");
+    }
+
+    const auto& database = toml::find(data, "database");
+    {
+        BOOST_TEST(toml::find<std::string>(database, "server") == "192.168.1.1");
+        const std::vector<int> expected_ports{8001, 8001, 8002};
+        BOOST_CHECK(toml::find<std::vector<int>>(database, "ports") == expected_ports);
+        BOOST_TEST(toml::find<int >(database, "connection_max") == 5000);
+        BOOST_TEST(toml::find<bool>(database, "enabled") == true);
+    }
+
+    const auto& servers = toml::find(data, "servers");
+    {
+        const auto& alpha = toml::find(servers, "alpha");
+        BOOST_TEST(alpha.comments().at(0) ==
+            " You can indent as you please. Tabs or spaces. TOML don't care.");
+        BOOST_TEST(toml::find<std::string>(alpha, "ip") == "10.0.0.1");
+        BOOST_TEST(toml::find<std::string>(alpha, "dc") == "eqdc10");
+
+        const auto& beta = toml::find(servers, "beta");
+        BOOST_TEST(toml::find<std::string>(beta, "ip") == "10.0.0.2");
+        BOOST_TEST(toml::find<std::string>(beta, "dc") == "eqdc10");
+        BOOST_TEST(toml::find<std::string>(beta, "country") ==
+                          "\xE4\xB8\xAD\xE5\x9B\xBD");
+        BOOST_TEST(toml::find(beta, "country").comments().at(0) ==
+                          " This should be parsed as UTF-8");
+    }
+
+    const auto& clients = toml::find(data, "clients");
+    {
+        BOOST_TEST(toml::find(clients, "data").comments().at(0) ==
+                " just an update to make sure parsers support it");
+
+
+        toml::array clients_data = toml::find<toml::array>(clients, "data");
+        std::vector<std::string> expected_name{"gamma", "delta"};
+        BOOST_CHECK(toml::get<std::vector<std::string>>(clients_data.at(0)) ==
+                    expected_name);
+        std::vector<int> expected_number{1, 2};
+        BOOST_CHECK(toml::get<std::vector<int>>(clients_data.at(1)) ==
+                    expected_number);
+        std::vector<std::string> expected_hosts{"alpha", "omega"};
+        BOOST_CHECK(toml::find<std::vector<std::string>>(clients, "hosts") ==
+                    expected_hosts);
+
+        BOOST_TEST(toml::find(clients, "hosts").comments().at(0) ==
+                    " Line breaks are OK when inside arrays");
+    }
+
+    std::vector<toml::table> products =
+        toml::find<std::vector<toml::table>>(data, "products");
+    {
+        BOOST_TEST(toml::get<std::string>(products.at(0).at("name")) ==
+                          "Hammer");
+        BOOST_TEST(toml::get<std::int64_t>(products.at(0).at("sku")) ==
+                          738594937);
+
+        BOOST_TEST(toml::get<std::string>(products.at(1).at("name")) ==
+                          "Nail");
+        BOOST_TEST(toml::get<std::int64_t>(products.at(1).at("sku")) ==
+                          284758393);
+        BOOST_TEST(toml::get<std::string>(products.at(1).at("color")) ==
+                          "gray");
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_example_preserve_stdmap_stddeque)
+{
+    const auto data = toml::parse<toml::preserve_comments, std::map, std::deque
+          >("toml/tests/example.toml");
+
+    static_assert(std::is_same<typename decltype(data)::table_type,
+            std::map<toml::key, typename std::remove_cv<decltype(data)>::type>
+            >::value, "");
+    static_assert(std::is_same<typename decltype(data)::array_type,
+            std::deque<typename std::remove_cv<decltype(data)>::type>
+            >::value, "");
+
+    BOOST_TEST(toml::find<std::string>(data, "title") == "TOML Example");
+    const auto& owner = toml::find(data, "owner");
+    {
+        BOOST_TEST(toml::find<std::string>(owner, "name") == "Tom Preston-Werner");
+        BOOST_TEST(toml::find<std::string>(owner, "organization") == "GitHub");
+        BOOST_TEST(toml::find<std::string>(owner, "bio") ==
+                          "GitHub Cofounder & CEO\nLikes tater tots and beer.");
+        BOOST_TEST(toml::find<toml::offset_datetime>(owner, "dob") ==
+                          toml::offset_datetime(toml::local_date(1979, toml::month_t::May, 27),
+                                                toml::local_time(7, 32, 0), toml::time_offset(0, 0)));
+        BOOST_TEST(toml::find(owner, "dob").comments().at(0) ==
+                          " First class dates? Why not?");
+    }
+
+    const auto& database = toml::find(data, "database");
+    {
+        BOOST_TEST(toml::find<std::string>(database, "server") == "192.168.1.1");
+        const std::vector<int> expected_ports{8001, 8001, 8002};
+        BOOST_CHECK(toml::find<std::vector<int>>(database, "ports") == expected_ports);
+        BOOST_TEST(toml::find<int >(database, "connection_max") == 5000);
+        BOOST_TEST(toml::find<bool>(database, "enabled") == true);
+    }
+
+    const auto& servers = toml::find(data, "servers");
+    {
+        const auto& alpha = toml::find(servers, "alpha");
+        BOOST_TEST(alpha.comments().at(0) ==
+            " You can indent as you please. Tabs or spaces. TOML don't care.");
+        BOOST_TEST(toml::find<std::string>(alpha, "ip") == "10.0.0.1");
+        BOOST_TEST(toml::find<std::string>(alpha, "dc") == "eqdc10");
+
+        const auto& beta = toml::find(servers, "beta");
+        BOOST_TEST(toml::find<std::string>(beta, "ip") == "10.0.0.2");
+        BOOST_TEST(toml::find<std::string>(beta, "dc") == "eqdc10");
+        BOOST_TEST(toml::find<std::string>(beta, "country") ==
+                          "\xE4\xB8\xAD\xE5\x9B\xBD");
+        BOOST_TEST(toml::find(beta, "country").comments().at(0) ==
+                          " This should be parsed as UTF-8");
+    }
+
+    const auto& clients = toml::find(data, "clients");
+    {
+        BOOST_TEST(toml::find(clients, "data").comments().at(0) ==
+                " just an update to make sure parsers support it");
+
+
+        toml::array clients_data = toml::find<toml::array>(clients, "data");
+        std::vector<std::string> expected_name{"gamma", "delta"};
+        BOOST_CHECK(toml::get<std::vector<std::string>>(clients_data.at(0)) ==
+                    expected_name);
+        std::vector<int> expected_number{1, 2};
+        BOOST_CHECK(toml::get<std::vector<int>>(clients_data.at(1)) ==
+                    expected_number);
+        std::vector<std::string> expected_hosts{"alpha", "omega"};
+        BOOST_CHECK(toml::find<std::vector<std::string>>(clients, "hosts") ==
+                    expected_hosts);
+
+        BOOST_TEST(toml::find(clients, "hosts").comments().at(0) ==
+                    " Line breaks are OK when inside arrays");
+    }
+
+    std::vector<toml::table> products =
+        toml::find<std::vector<toml::table>>(data, "products");
+    {
+        BOOST_TEST(toml::get<std::string>(products.at(0).at("name")) ==
+                          "Hammer");
+        BOOST_TEST(toml::get<std::int64_t>(products.at(0).at("sku")) ==
+                          738594937);
+
+        BOOST_TEST(toml::get<std::string>(products.at(1).at("name")) ==
+                          "Nail");
+        BOOST_TEST(toml::get<std::int64_t>(products.at(1).at("sku")) ==
+                          284758393);
+        BOOST_TEST(toml::get<std::string>(products.at(1).at("color")) ==
+                          "gray");
+    }
+}
 
 // ---------------------------------------------------------------------------
 // after here, the test codes generate the content of a file.
@@ -210,8 +403,8 @@ BOOST_AUTO_TEST_CASE(test_file_with_BOM)
         std::istringstream iss(table);
         const auto data = toml::parse(iss, "test_file_with_BOM.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -226,8 +419,8 @@ BOOST_AUTO_TEST_CASE(test_file_with_BOM)
         }
         const auto data = toml::parse("tmp.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -239,8 +432,8 @@ BOOST_AUTO_TEST_CASE(test_file_with_BOM)
         std::istringstream iss(table);
         const auto data = toml::parse(iss, "test_file_with_BOM_CRLF.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -254,12 +447,12 @@ BOOST_AUTO_TEST_CASE(test_file_with_BOM)
             // value will be "\r\r\n". To avoid the additional "\r", use binary
             // mode.
             std::ofstream ofs("tmp.toml", std::ios_base::binary);
-            ofs.write(table.data(), table.size());
+            ofs.write(table.data(), static_cast<std::streamsize>(table.size()));
         }
         const auto data = toml::parse("tmp.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 }
 
@@ -275,8 +468,8 @@ BOOST_AUTO_TEST_CASE(test_file_without_newline_at_the_end_of_file)
         const auto data = toml::parse(iss,
                 "test_file_without_newline_at_the_end_of_file.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -288,8 +481,8 @@ BOOST_AUTO_TEST_CASE(test_file_without_newline_at_the_end_of_file)
         const auto data = toml::parse(iss,
                 "test_file_without_newline_at_the_end_of_file_CRLF.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 
     {
@@ -302,8 +495,8 @@ BOOST_AUTO_TEST_CASE(test_file_without_newline_at_the_end_of_file)
         const auto data = toml::parse(iss,
                 "test_file_without_newline_at_the_end_of_file_comment.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -315,8 +508,8 @@ BOOST_AUTO_TEST_CASE(test_file_without_newline_at_the_end_of_file)
         const auto data = toml::parse(iss,
                 "test_file_without_newline_at_the_end_of_file_comment.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 
     {
@@ -329,8 +522,8 @@ BOOST_AUTO_TEST_CASE(test_file_without_newline_at_the_end_of_file)
         const auto data = toml::parse(iss,
                 "test_file_without_newline_at_the_end_of_file_ws.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -342,8 +535,8 @@ BOOST_AUTO_TEST_CASE(test_file_without_newline_at_the_end_of_file)
         const auto data = toml::parse(iss,
                 "test_file_without_newline_at_the_end_of_file_ws.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 }
 
@@ -362,8 +555,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_comment)
         const auto data = toml::parse(iss,
                 "test_files_end_with_comment.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -377,8 +570,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_comment)
         const auto data = toml::parse(iss,
                 "test_files_end_with_comment.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 
     // comment w/ newline
@@ -394,8 +587,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_comment)
         const auto data = toml::parse(iss,
                 "test_files_end_with_comment.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -409,8 +602,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_comment)
         const auto data = toml::parse(iss,
                 "test_files_end_with_comment.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 
     // CRLF version
@@ -426,8 +619,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_comment)
         const auto data = toml::parse(iss,
                 "test_files_end_with_comment.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -441,8 +634,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_comment)
         const auto data = toml::parse(iss,
                 "test_files_end_with_comment.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -455,8 +648,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_comment)
         const auto data = toml::parse(iss,
                 "test_files_end_with_comment.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -470,8 +663,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_comment)
         const auto data = toml::parse(iss,
                 "test_files_end_with_comment.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 }
 
@@ -489,8 +682,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -504,8 +697,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 
     // with whitespaces
@@ -521,8 +714,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -536,8 +729,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -551,8 +744,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -566,8 +759,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 
     // with whitespaces but no newline
@@ -582,8 +775,24 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
+    }
+
+    // without newline
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "a = 0"
+            );
+        std::istringstream iss(table);
+        const auto data = toml::parse(iss,
+                "test_files_end_with_newline.toml");
+
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 
 
@@ -600,8 +809,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -615,8 +824,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 
     // with whitespaces
@@ -632,8 +841,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -647,8 +856,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -662,8 +871,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -677,8 +886,8 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
     {
         const std::string table(
@@ -691,7 +900,46 @@ BOOST_AUTO_TEST_CASE(test_files_end_with_empty_lines)
         const auto data = toml::parse(iss,
                 "test_files_end_with_newline.toml");
 
-        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
-        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+        BOOST_TEST(toml::find<std::string>(data, "key") == "value");
+        BOOST_TEST(toml::find<std::string>(toml::find(data, "table"), "key") == "value");
     }
 }
+
+
+BOOST_AUTO_TEST_CASE(test_parse_function_compiles)
+{
+    // toml::parse("");
+    const auto string_literal = toml::parse("toml/tests/example.toml");
+
+    BOOST_TEST_MESSAGE("string_literal");
+
+    const char* fname_cstring = "toml/tests/example.toml";
+    // toml::parse(const char*);
+    const auto cstring = toml::parse(fname_cstring);
+
+    BOOST_TEST_MESSAGE("const char*");
+
+    // toml::parse(char*);
+    std::array<char, 24> fname_char_ptr;
+    std::strncpy(fname_char_ptr.data(), fname_cstring, 24);
+    const auto char_ptr = toml::parse(fname_char_ptr.data());
+
+    BOOST_TEST_MESSAGE("char*");
+
+    // toml::parse(const std::string&);
+    const std::string fname_string("toml/tests/example.toml");
+    const auto string = toml::parse(fname_string);
+    std::string fname_string_mut("toml/tests/example.toml");
+    // toml::parse(std::string&);
+    const auto string_mutref = toml::parse(fname_string_mut);
+    // toml::parse(std::string&&);
+    const auto string_rref = toml::parse(std::move(fname_string_mut));
+
+    BOOST_TEST_MESSAGE("strings");
+
+#ifdef TOML11_HAS_STD_FILESYSTEM
+    const std::filesystem::path fname_path(fname_string.begin(), fname_string.end());
+    const auto filesystem_path = toml::parse(fname_path);
+    BOOST_TEST_MESSAGE("path");
+#endif
+}

tests/test_parse_floating.cpp

@@ -32,20 +32,20 @@ BOOST_AUTO_TEST_CASE(test_fractional)
 
 BOOST_AUTO_TEST_CASE(test_fractional_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1.0",               value( 1.0));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0.1",               value( 0.1));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0.001",             value( 0.001));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0.100",             value( 0.1));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "+3.14",             value( 3.14));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "-3.14",             value(-3.14));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "3.1415_9265_3589",  value( 3.141592653589));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "+3.1415_9265_3589", value( 3.141592653589));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "-3.1415_9265_3589", value(-3.141592653589));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "123_456.789",       value( 123456.789));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "+123_456.789",      value( 123456.789));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "-123_456.789",      value(-123456.789));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "+0.0",              value( 0.0));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "-0.0",              value(-0.0));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1.0",               value( 1.0));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0.1",               value( 0.1));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0.001",             value( 0.001));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0.100",             value( 0.1));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "+3.14",             value( 3.14));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "-3.14",             value(-3.14));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "3.1415_9265_3589",  value( 3.141592653589));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "+3.1415_9265_3589", value( 3.141592653589));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "-3.1415_9265_3589", value(-3.141592653589));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "123_456.789",       value( 123456.789));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "+123_456.789",      value( 123456.789));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "-123_456.789",      value(-123456.789));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "+0.0",              value( 0.0));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "-0.0",              value(-0.0));
 }
 
 BOOST_AUTO_TEST_CASE(test_exponential)
@@ -68,28 +68,42 @@ BOOST_AUTO_TEST_CASE(test_exponential)
     TOML11_TEST_PARSE_EQUAL(parse_floating, "1_2_3E-1_0", 123e-10);
     TOML11_TEST_PARSE_EQUAL(parse_floating, "+0e0",        0.0);
     TOML11_TEST_PARSE_EQUAL(parse_floating, "-0e0",       -0.0);
+
+#ifdef TOML11_USE_UNRELEASED_TOML_FEATURES
+    BOOST_TEST_MESSAGE("testing an unreleased toml feature: leading zeroes in float exponent part");
+    // toml-lang/toml master permits leading 0s in exp part (unreleased)
+    TOML11_TEST_PARSE_EQUAL(parse_floating, "1_2_3E-01",  123e-1);
+    TOML11_TEST_PARSE_EQUAL(parse_floating, "1_2_3E-0_1", 123e-1);
+#endif
 }
 
 BOOST_AUTO_TEST_CASE(test_exponential_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1e10",       value(1e10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1e+10",      value(1e10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1e-10",      value(1e-10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "+1e10",      value(1e10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "+1e+10",     value(1e10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "+1e-10",     value(1e-10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "-1e10",      value(-1e10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "-1e+10",     value(-1e10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "-1e-10",     value(-1e-10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "123e-10",    value(123e-10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1E10",       value(1e10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1E+10",      value(1e10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1E-10",      value(1e-10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "123E-10",    value(123e-10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1_2_3E-10",  value(123e-10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1_2_3E-1_0", value(123e-10));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "+0e0",       value( 0.0));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "-0e0",       value(-0.0));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1e10",       value(1e10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1e+10",      value(1e10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1e-10",      value(1e-10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "+1e10",      value(1e10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "+1e+10",     value(1e10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "+1e-10",     value(1e-10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "-1e10",      value(-1e10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "-1e+10",     value(-1e10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "-1e-10",     value(-1e-10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "123e-10",    value(123e-10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1E10",       value(1e10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1E+10",      value(1e10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1E-10",      value(1e-10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "123E-10",    value(123e-10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1_2_3E-10",  value(123e-10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1_2_3E-1_0", value(123e-10));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "+0e0",       value( 0.0));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "-0e0",       value(-0.0));
+
+#ifdef TOML11_USE_UNRELEASED_TOML_FEATURES
+    BOOST_TEST_MESSAGE("testing an unreleased toml feature: leading zeroes in float exponent part");
+    // toml-lang/toml master permits leading 0s in exp part (unreleased)
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1_2_3E-01",  value(123e-1));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1_2_3E-0_1", value(123e-1));
+#endif
 }
 BOOST_AUTO_TEST_CASE(test_fe)
 {
@@ -99,16 +113,22 @@ BOOST_AUTO_TEST_CASE(test_fe)
 }
 BOOST_AUTO_TEST_CASE(test_fe_vaule)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "6.02e23",          value(6.02e23));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "6.02e+23",         value(6.02e23));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "1.112_650_06e-17", value(1.11265006e-17));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "6.02e23",          value(6.02e23));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "6.02e+23",         value(6.02e23));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "1.112_650_06e-17", value(1.11265006e-17));
+
+#ifdef TOML11_USE_UNRELEASED_TOML_FEATURES
+    BOOST_TEST_MESSAGE("testing an unreleased toml feature: leading zeroes in float exponent part");
+    // toml-lang/toml master permits leading 0s in exp part (unreleased)
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "3.141_5e-01",      value(3.1415e-1));
+#endif
 }
 
 BOOST_AUTO_TEST_CASE(test_inf)
 {
     {
         const std::string token("inf");
-        toml::detail::location<std::string> loc("test", token);
+        toml::detail::location loc("test", token);
         const auto r = parse_floating(loc);
         BOOST_CHECK(r.is_ok());
         BOOST_CHECK(std::isinf(r.unwrap().first));
@@ -116,7 +136,7 @@ BOOST_AUTO_TEST_CASE(test_inf)
     }
     {
         const std::string token("+inf");
-        toml::detail::location<std::string> loc("test", token);
+        toml::detail::location loc("test", token);
         const auto r = parse_floating(loc);
         BOOST_CHECK(r.is_ok());
         BOOST_CHECK(std::isinf(r.unwrap().first));
@@ -124,7 +144,7 @@ BOOST_AUTO_TEST_CASE(test_inf)
     }
     {
         const std::string token("-inf");
-        toml::detail::location<std::string> loc("test", token);
+        toml::detail::location loc("test", token);
         const auto r = parse_floating(loc);
         BOOST_CHECK(r.is_ok());
         BOOST_CHECK(std::isinf(r.unwrap().first));
@@ -136,21 +156,21 @@ BOOST_AUTO_TEST_CASE(test_nan)
 {
     {
         const std::string token("nan");
-        toml::detail::location<std::string> loc("test", token);
+        toml::detail::location loc("test", token);
         const auto r = parse_floating(loc);
         BOOST_CHECK(r.is_ok());
         BOOST_CHECK(std::isnan(r.unwrap().first));
     }
     {
         const std::string token("+nan");
-        toml::detail::location<std::string> loc("test", token);
+        toml::detail::location loc("test", token);
         const auto r = parse_floating(loc);
         BOOST_CHECK(r.is_ok());
         BOOST_CHECK(std::isnan(r.unwrap().first));
     }
     {
         const std::string token("-nan");
-        toml::detail::location<std::string> loc("test", token);
+        toml::detail::location loc("test", token);
         const auto r = parse_floating(loc);
         BOOST_CHECK(r.is_ok());
         BOOST_CHECK(std::isnan(r.unwrap().first));

tests/test_parse_inline_table.cpp

@@ -13,36 +13,52 @@ using namespace detail;
 
 BOOST_AUTO_TEST_CASE(test_inline_table)
 {
-    TOML11_TEST_PARSE_EQUAL(parse_inline_table, "{}", table());
+    TOML11_TEST_PARSE_EQUAL(parse_inline_table<toml::value>, "{}", table());
     {
         table t;
         t["foo"] = toml::value(42);
         t["bar"] = toml::value("baz");
-        TOML11_TEST_PARSE_EQUAL(parse_inline_table, "{foo = 42, bar = \"baz\"}", t);
+        TOML11_TEST_PARSE_EQUAL(parse_inline_table<toml::value>, "{foo = 42, bar = \"baz\"}", t);
     }
     {
         table t;
         table t_sub;
         t_sub["name"] = toml::value("pug");
         t["type"] = toml::value(t_sub);
-        TOML11_TEST_PARSE_EQUAL(parse_inline_table, "{type.name = \"pug\"}", t);
+        TOML11_TEST_PARSE_EQUAL(parse_inline_table<toml::value>, "{type.name = \"pug\"}", t);
     }
 }
 
 BOOST_AUTO_TEST_CASE(test_inline_table_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "{}", value(table()));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "{}", value(table()));
     {
         table t;
         t["foo"] = toml::value(42);
         t["bar"] = toml::value("baz");
-        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "{foo = 42, bar = \"baz\"}", value(t));
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "{foo = 42, bar = \"baz\"}", value(t));
     }
     {
         table t;
         table t_sub;
         t_sub["name"] = toml::value("pug");
         t["type"] = toml::value(t_sub);
-        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "{type.name = \"pug\"}", value(t));
+        TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "{type.name = \"pug\"}", value(t));
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_inline_table_immutability)
+{
+    {
+        std::istringstream stream(std::string(
+                "a = {b = 1}\n"
+                "a.c = 2\n"));
+        BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
+    }
+    {
+        std::istringstream stream(std::string(
+                "a = {b = {c = 1}}\n"
+                "a.b.d = 2\n"));
+        BOOST_CHECK_THROW(toml::parse(stream), toml::syntax_error);
     }
 }

tests/test_parse_integer.cpp

@@ -25,14 +25,14 @@ BOOST_AUTO_TEST_CASE(test_decimal)
 
 BOOST_AUTO_TEST_CASE(test_decimal_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value,        "1234", toml::value(     1234));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value,       "+1234", toml::value(     1234));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value,       "-1234", toml::value(    -1234));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value,           "0", toml::value(        0));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value,     "1_2_3_4", toml::value(     1234));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value,    "+1_2_3_4", toml::value(    +1234));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value,    "-1_2_3_4", toml::value(    -1234));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "123_456_789", toml::value(123456789));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,        "1234", toml::value(     1234));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,       "+1234", toml::value(     1234));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,       "-1234", toml::value(    -1234));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,           "0", toml::value(        0));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,     "1_2_3_4", toml::value(     1234));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,    "+1_2_3_4", toml::value(    +1234));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,    "-1_2_3_4", toml::value(    -1234));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "123_456_789", toml::value(123456789));
 }
 
 BOOST_AUTO_TEST_CASE(test_hex)
@@ -50,15 +50,15 @@ BOOST_AUTO_TEST_CASE(test_hex)
 
 BOOST_AUTO_TEST_CASE(test_hex_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0xDEADBEEF",  value(0xDEADBEEF));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0xdeadbeef",  value(0xDEADBEEF));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0xDEADbeef",  value(0xDEADBEEF));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0xDEAD_BEEF", value(0xDEADBEEF));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0xdead_beef", value(0xDEADBEEF));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0xdead_BEEF", value(0xDEADBEEF));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0xFF",        value(0xFF));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0x00FF",      value(0xFF));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0x0000FF",    value(0xFF));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0xDEADBEEF",  value(0xDEADBEEF));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0xdeadbeef",  value(0xDEADBEEF));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0xDEADbeef",  value(0xDEADBEEF));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0xDEAD_BEEF", value(0xDEADBEEF));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0xdead_beef", value(0xDEADBEEF));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0xdead_BEEF", value(0xDEADBEEF));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0xFF",        value(0xFF));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0x00FF",      value(0xFF));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0x0000FF",    value(0xFF));
 }
 
 BOOST_AUTO_TEST_CASE(test_oct)
@@ -70,9 +70,9 @@ BOOST_AUTO_TEST_CASE(test_oct)
 
 BOOST_AUTO_TEST_CASE(test_oct_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0o777",   value(64*7+8*7+7));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0o7_7_7", value(64*7+8*7+7));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0o007",   value(7));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0o777",   value(64*7+8*7+7));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0o7_7_7", value(64*7+8*7+7));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0o007",   value(7));
 }
 
 BOOST_AUTO_TEST_CASE(test_bin)
@@ -85,8 +85,8 @@ BOOST_AUTO_TEST_CASE(test_bin)
 
 BOOST_AUTO_TEST_CASE(test_bin_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0b10000",    value(16));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0b010000",   value(16));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0b01_00_00", value(16));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, "0b111111",   value(63));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0b10000",    value(16));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0b010000",   value(16));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0b01_00_00", value(16));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>, "0b111111",   value(63));
 }

tests/test_parse_string.cpp

@@ -29,16 +29,16 @@ BOOST_AUTO_TEST_CASE(test_string)
 
 BOOST_AUTO_TEST_CASE(test_string_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "\"The quick brown fox jumps over the lazy dog\"",
         toml::value("The quick brown fox jumps over the lazy dog", string_t::basic));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "\'The quick brown fox jumps over the lazy dog\'",
         toml::value("The quick brown fox jumps over the lazy dog", string_t::literal));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "\"\"\"The quick brown fox \\\njumps over the lazy dog\"\"\"",
         toml::value("The quick brown fox jumps over the lazy dog", string_t::basic));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "'''The quick brown fox \njumps over the lazy dog'''",
         toml::value("The quick brown fox \njumps over the lazy dog", string_t::literal));
 }
@@ -69,31 +69,37 @@ BOOST_AUTO_TEST_CASE(test_basic_string)
     TOML11_TEST_PARSE_EQUAL(parse_string,
         "\" And when \\\"'s are in the along with # \\\"\"",
         string(" And when \"'s are in the along with # \"", string_t::basic));
+    TOML11_TEST_PARSE_EQUAL(parse_string,
+        "\"Here are fifteen apostrophes: '''''''''''''''\"",
+        string("Here are fifteen apostrophes: '''''''''''''''", string_t::basic));
 }
 
 BOOST_AUTO_TEST_CASE(test_basic_string_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "\"GitHub Cofounder & CEO\\nLikes tater tots and beer.\"",
         value("GitHub Cofounder & CEO\nLikes tater tots and beer.", string_t::basic));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "\"192.168.1.1\"",
         value("192.168.1.1", string_t::basic));
 #if defined(_MSC_VER) || defined(__INTEL_COMPILER)
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value,
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "\"\xE4\xB8\xAD\xE5\x9B\xBD\"",
         value("\xE4\xB8\xAD\xE5\x9B\xBD", string_t::basic));
 #else
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "\"中国\"",
         value("中国", string_t::basic));
 #endif
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "\"You'll hate me after this - #\"",
         value("You'll hate me after this - #", string_t::basic));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "\" And when \\\"'s are in the along with # \\\"\"",
         value(" And when \"'s are in the along with # \"", string_t::basic));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
+        "\"Here are fifteen apostrophes: '''''''''''''''\"",
+        value("Here are fifteen apostrophes: '''''''''''''''", string_t::basic));
 }
 
 BOOST_AUTO_TEST_CASE(test_ml_basic_string)
@@ -104,16 +110,41 @@ BOOST_AUTO_TEST_CASE(test_ml_basic_string)
     TOML11_TEST_PARSE_EQUAL(parse_string,
         "\"\"\"\\\n  The quick brown \\\n\n  fox jumps over \\\n  the lazy dog.\\\n  \"\"\"",
         string("The quick brown fox jumps over the lazy dog.", string_t::basic));
+    TOML11_TEST_PARSE_EQUAL(parse_string,
+        "\"\"\"Here are two quotation marks: \"\". Simple enough.\"\"\"",
+        string("Here are two quotation marks: \"\". Simple enough.", string_t::basic));
+    TOML11_TEST_PARSE_EQUAL(parse_string,
+        "\"\"\"Here are three quotation marks: \"\"\\\".\"\"\"",
+        string("Here are three quotation marks: \"\"\".", string_t::basic));
+    TOML11_TEST_PARSE_EQUAL(parse_string,
+        "\"\"\"Here are fifteen quotation marks: \"\"\\\"\"\"\\\"\"\"\\\"\"\"\\\"\"\"\\\".\"\"\"",
+        string("Here are fifteen quotation marks: \"\"\"\"\"\"\"\"\"\"\"\"\"\"\".", string_t::basic));
+    TOML11_TEST_PARSE_EQUAL(parse_string,
+        "\"\"\"\"This,\" she said, \"is just a pointless statement.\"\"\"\"",
+        string("\"This,\" she said, \"is just a pointless statement.\"", string_t::basic));
 }
 
 BOOST_AUTO_TEST_CASE(test_ml_basic_string_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "\"\"\"\nThe quick brown \\\n\n  fox jumps over \\\n  the lazy dog.\"\"\"",
         value("The quick brown fox jumps over the lazy dog.", string_t::basic));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "\"\"\"\\\n  The quick brown \\\n\n  fox jumps over \\\n  the lazy dog.\\\n  \"\"\"",
         value("The quick brown fox jumps over the lazy dog.", string_t::basic));
+
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
+        "\"\"\"Here are two quotation marks: \"\". Simple enough.\"\"\"",
+        value("Here are two quotation marks: \"\". Simple enough.", string_t::basic));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
+        "\"\"\"Here are three quotation marks: \"\"\\\".\"\"\"",
+        value("Here are three quotation marks: \"\"\".", string_t::basic));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
+        "\"\"\"Here are fifteen quotation marks: \"\"\\\"\"\"\\\"\"\"\\\"\"\"\\\"\"\"\\\".\"\"\"",
+        value("Here are fifteen quotation marks: \"\"\"\"\"\"\"\"\"\"\"\"\"\"\".", string_t::basic));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
+        "\"\"\"\"This,\" she said, \"is just a pointless statement.\"\"\"\"",
+        value("\"This,\" she said, \"is just a pointless statement.\"", string_t::basic));
 }
 
 BOOST_AUTO_TEST_CASE(test_literal_string)
@@ -134,16 +165,16 @@ BOOST_AUTO_TEST_CASE(test_literal_string)
 
 BOOST_AUTO_TEST_CASE(test_literal_string_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "'C:\\Users\\nodejs\\templates'",
         value("C:\\Users\\nodejs\\templates", string_t::literal));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "'\\\\ServerX\\admin$\\system32\\'",
         value("\\\\ServerX\\admin$\\system32\\", string_t::literal));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "'Tom \"Dubs\" Preston-Werner'",
         value("Tom \"Dubs\" Preston-Werner", string_t::literal));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "'<\\i\\c*\\s*>'",
         value("<\\i\\c*\\s*>", string_t::literal));
 }
@@ -156,16 +187,34 @@ BOOST_AUTO_TEST_CASE(test_ml_literal_string)
     TOML11_TEST_PARSE_EQUAL(parse_string,
         "'''\nThe first newline is\ntrimmed in raw strings.\n   All other whitespace\n   is preserved.\n'''",
         string("The first newline is\ntrimmed in raw strings.\n   All other whitespace\n   is preserved.\n", string_t::literal));
+    TOML11_TEST_PARSE_EQUAL(parse_string,
+        "''''That's still pointless', she said.'''",
+        string("'That's still pointless', she said.", string_t::literal));
+    TOML11_TEST_PARSE_EQUAL(parse_string,
+        "'''Here are fifteen quotation marks: \"\"\"\"\"\"\"\"\"\"\"\"\"\"\".'''",
+        string("Here are fifteen quotation marks: \"\"\"\"\"\"\"\"\"\"\"\"\"\"\".", string_t::literal));
+    TOML11_TEST_PARSE_EQUAL(parse_string,
+        "''''This,' she said, 'is just a pointless statement.''''",
+        string("'This,' she said, 'is just a pointless statement.'", string_t::literal));
 }
 
 BOOST_AUTO_TEST_CASE(test_ml_literal_string_value)
 {
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "'''I [dw]on't need \\d{2} apples'''",
         value("I [dw]on't need \\d{2} apples", string_t::literal));
-    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value, 
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
         "'''\nThe first newline is\ntrimmed in raw strings.\n   All other whitespace\n   is preserved.\n'''",
         value("The first newline is\ntrimmed in raw strings.\n   All other whitespace\n   is preserved.\n", string_t::literal));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
+        "''''That's still pointless', she said.'''",
+        value("'That's still pointless', she said.", string_t::literal));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
+        "'''Here are fifteen quotation marks: \"\"\"\"\"\"\"\"\"\"\"\"\"\"\".'''",
+        value("Here are fifteen quotation marks: \"\"\"\"\"\"\"\"\"\"\"\"\"\"\".", string_t::literal));
+    TOML11_TEST_PARSE_EQUAL_VALUE(parse_value<toml::value>,
+        "''''This,' she said, 'is just a pointless statement.''''",
+        value("'This,' she said, 'is just a pointless statement.'", string_t::literal));
 }
 
 BOOST_AUTO_TEST_CASE(test_unicode_escape_sequence)

tests/test_parse_table.cpp

@@ -19,15 +19,15 @@ BOOST_AUTO_TEST_CASE(test_normal_table)
         "key2 = 42\n"
         "key3 = 3.14\n"
         );
-    location<std::string> loc("test", table);
+    location loc("test", table);
 
-    const auto result = toml::detail::parse_ml_table(loc);
-    BOOST_CHECK(result.is_ok());
+    const auto result = toml::detail::parse_ml_table<toml::value>(loc);
+    BOOST_TEST(result.is_ok());
     const auto data = result.unwrap();
 
-    BOOST_CHECK_EQUAL(toml::get<std::string >(data.at("key1")), "value");
-    BOOST_CHECK_EQUAL(toml::get<std::int64_t>(data.at("key2")), 42);
-    BOOST_CHECK_EQUAL(toml::get<double      >(data.at("key3")), 3.14);
+    BOOST_TEST(toml::get<std::string >(data.at("key1")) == "value");
+    BOOST_TEST(toml::get<std::int64_t>(data.at("key2")) == 42);
+    BOOST_TEST(toml::get<double      >(data.at("key3")) == 3.14);
 }
 
 BOOST_AUTO_TEST_CASE(test_nested_table)
@@ -36,15 +36,15 @@ BOOST_AUTO_TEST_CASE(test_nested_table)
         "a.b   = \"value\"\n"
         "a.c.d = 42\n"
         );
-    location<std::string> loc("test", table);
+    location loc("test", table);
 
-    const auto result = toml::detail::parse_ml_table(loc);
-    BOOST_CHECK(result.is_ok());
+    const auto result = toml::detail::parse_ml_table<toml::value>(loc);
+    BOOST_TEST(result.is_ok());
     const auto data = result.unwrap();
 
     const auto a = toml::get<toml::table>(data.at("a"));
     const auto c = toml::get<toml::table>(a.at("c"));
 
-    BOOST_CHECK_EQUAL(toml::get<std::string >(a.at("b")), "value");
-    BOOST_CHECK_EQUAL(toml::get<std::int64_t>(c.at("d")), 42);
+    BOOST_TEST(toml::get<std::string >(a.at("b")) == "value");
+    BOOST_TEST(toml::get<std::int64_t>(c.at("d")) == 42);
 }

tests/test_parse_unicode.cpp

@@ -9,16 +9,15 @@
 #include <iostream>
 #include <fstream>
 
-#if defined(_MSC_VER) || defined(__INTEL_COMPILER)
 BOOST_AUTO_TEST_CASE(test_hard_example_unicode)
 {
     const auto data = toml::parse("toml/tests/hard_example_unicode.toml");
 
-    const auto the = toml::get<toml::Table>(data.at("the"));
-    BOOST_CHECK_EQUAL(toml::get<std::string>(the.at("test_string")),
+    const auto the = toml::find<toml::table>(data, "the");
+    BOOST_TEST(toml::get<std::string>(the.at("test_string")) ==
                       std::string("\xC3\x9D\xC3\xB4\xC3\xBA\x27\xE2\x84\x93\xE2\x84\x93\x20\xCE\xBB\xC3\xA1\xC6\xAD\xC3\xA8\x20\xE2\x82\xA5\xC3\xA8\x20\xC3\xA1\xC6\x92\xC6\xAD\xC3\xA8\xC5\x99\x20\xC6\xAD\xCE\xBB\xC3\xAF\xC6\xA8\x20\x2D\x20\x23"));
 
-    const auto hard = toml::get<toml::Table>(the.at("hard"));
+    const auto hard = toml::get<toml::table>(the.at("hard"));
     const std::vector<std::string> expected_the_hard_test_array{"] ", " # "};
     BOOST_CHECK(toml::get<std::vector<std::string>>(hard.at("test_array")) ==
                 expected_the_hard_test_array);
@@ -28,47 +27,15 @@ BOOST_AUTO_TEST_CASE(test_hard_example_unicode)
     };
     BOOST_CHECK(toml::get<std::vector<std::string>>(hard.at("test_array2")) ==
                 expected_the_hard_test_array2);
-    BOOST_CHECK_EQUAL(toml::get<std::string>(hard.at("another_test_string")),
+    BOOST_TEST(toml::get<std::string>(hard.at("another_test_string")) ==
                       std::string("\xC2\xA7\xC3\xA1\xE2\x82\xA5\xC3\xA8\x20\xC6\xAD\xCE\xBB\xC3\xAF\xC3\xB1\xCF\xB1\x2C\x20\xCE\xB2\xC3\xBA\xC6\xAD\x20\xCF\x89\xC3\xAF\xC6\xAD\xCE\xBB\x20\xC3\xA1\x20\xC6\xA8\xC6\xAD\xC5\x99\xC3\xAF\xC3\xB1\xCF\xB1\x20\x23"));
-    BOOST_CHECK_EQUAL(toml::get<std::string>(hard.at("harder_test_string")),
+    BOOST_TEST(toml::get<std::string>(hard.at("harder_test_string")) ==
                       std::string("\x20\xC3\x82\xC3\xB1\xCE\xB4\x20\xCF\x89\xCE\xBB\xC3\xA8\xC3\xB1\x20\x22\x27\xC6\xA8\x20\xC3\xA1\xC5\x99\xC3\xA8\x20\xC3\xAF\xC3\xB1\x20\xC6\xAD\xCE\xBB\xC3\xA8\x20\xC6\xA8\xC6\xAD\xC5\x99\xC3\xAF\xC3\xB1\xCF\xB1\x2C\x20\xC3\xA1\xE2\x84\x93\xC3\xB4\xC3\xB1\xCF\xB1\x20\xCF\x89\xC3\xAF\xC6\xAD\xCE\xBB\x20\x23\x20\x22"));
 //
-    const auto bit = toml::get<toml::Table>(hard.at(std::string("\xCE\xB2\xC3\xAF\xC6\xAD\x23")));
-    BOOST_CHECK_EQUAL(toml::get<std::string>(bit.at(std::string("\xCF\x89\xCE\xBB\xC3\xA1\xC6\xAD\x3F"))),
+    const auto bit = toml::get<toml::table>(hard.at(std::string("\xCE\xB2\xC3\xAF\xC6\xAD\x23")));
+    BOOST_TEST(toml::get<std::string>(bit.at(std::string("\xCF\x89\xCE\xBB\xC3\xA1\xC6\xAD\x3F"))) ==
         std::string("\xC3\x9D\xC3\xB4\xC3\xBA\x20\xCE\xB4\xC3\xB4\xC3\xB1\x27\xC6\xAD\x20\xC6\xAD\xCE\xBB\xC3\xAF\xC3\xB1\xC6\x99\x20\xC6\xA8\xC3\xB4\xE2\x82\xA5\xC3\xA8\x20\xC3\xBA\xC6\xA8\xC3\xA8\xC5\x99\x20\xCF\x89\xC3\xB4\xC3\xB1\x27\xC6\xAD\x20\xCE\xB4\xC3\xB4\x20\xC6\xAD\xCE\xBB\xC3\xA1\xC6\xAD\x3F"));
     const std::vector<std::string> expected_multi_line_array{"]"};
     BOOST_CHECK(toml::get<std::vector<std::string>>(bit.at("multi_line_array")) ==
                 expected_multi_line_array);
 }
-#else
-BOOST_AUTO_TEST_CASE(test_hard_example_unicode)
-{
-    const auto data = toml::parse("toml/tests/hard_example_unicode.toml");
-
-    const auto the = toml::get<toml::Table>(data.at("the"));
-    BOOST_CHECK_EQUAL(toml::get<std::string>(the.at("test_string")),
-                      std::string(u8"Ýôú'ℓℓ λáƭè ₥è áƒƭèř ƭλïƨ - #"));
-
-    const auto hard = toml::get<toml::Table>(the.at("hard"));
-    const std::vector<std::string> expected_the_hard_test_array{"] ", " # "};
-    BOOST_CHECK(toml::get<std::vector<std::string>>(hard.at("test_array")) ==
-                expected_the_hard_test_array);
-    const std::vector<std::string> expected_the_hard_test_array2{
-            std::string(u8"Tèƨƭ #11 ]ƥřôƲèδ ƭλáƭ"),
-            std::string(u8"Éжƥèřï₥èñƭ #9 ωáƨ á ƨúççèƨƨ")};
-    BOOST_CHECK(toml::get<std::vector<std::string>>(hard.at("test_array2")) ==
-                expected_the_hard_test_array2);
-    BOOST_CHECK_EQUAL(toml::get<std::string>(hard.at("another_test_string")),
-                      std::string(u8"§á₥è ƭλïñϱ, βúƭ ωïƭλ á ƨƭřïñϱ #"));
-    BOOST_CHECK_EQUAL(toml::get<std::string>(hard.at("harder_test_string")),
-                      std::string(u8" Âñδ ωλèñ \"'ƨ ářè ïñ ƭλè ƨƭřïñϱ, áℓôñϱ ωïƭλ # \""));
-
-    const auto bit = toml::get<toml::Table>(hard.at(std::string(u8"βïƭ#")));
-    BOOST_CHECK_EQUAL(toml::get<std::string>(bit.at(std::string(u8"ωλáƭ?"))),
-                      std::string(u8"Ýôú δôñ'ƭ ƭλïñƙ ƨô₥è úƨèř ωôñ'ƭ δô ƭλáƭ?"));
-    const std::vector<std::string> expected_multi_line_array{"]"};
-    BOOST_CHECK(toml::get<std::vector<std::string>>(bit.at("multi_line_array")) ==
-                expected_multi_line_array);
-
-}
-#endif

tests/test_result.cpp

@@ -8,49 +8,49 @@ BOOST_AUTO_TEST_CASE(test_construct)
     {
         auto s = toml::ok(42);
         toml::result<int, std::string> result(s);
-        BOOST_CHECK(!!result);
-        BOOST_CHECK(result.is_ok());
-        BOOST_CHECK(!result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap(), 42);
+        BOOST_TEST(!!result);
+        BOOST_TEST(result.is_ok());
+        BOOST_TEST(!result.is_err());
+        BOOST_TEST(result.unwrap() == 42);
     }
     {
         const auto s = toml::ok(42);
         toml::result<int, std::string> result(s);
-        BOOST_CHECK(!!result);
-        BOOST_CHECK(result.is_ok());
-        BOOST_CHECK(!result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap(), 42);
+        BOOST_TEST(!!result);
+        BOOST_TEST(result.is_ok());
+        BOOST_TEST(!result.is_err());
+        BOOST_TEST(result.unwrap() == 42);
     }
     {
         toml::result<int, std::string> result(toml::ok(42));
-        BOOST_CHECK(!!result);
-        BOOST_CHECK(result.is_ok());
-        BOOST_CHECK(!result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap(), 42);
+        BOOST_TEST(!!result);
+        BOOST_TEST(result.is_ok());
+        BOOST_TEST(!result.is_err());
+        BOOST_TEST(result.unwrap() == 42);
     }
 
     {
         auto f = toml::err<std::string>("foobar");
         toml::result<int, std::string> result(f);
-        BOOST_CHECK(!result);
-        BOOST_CHECK(!result.is_ok());
-        BOOST_CHECK(result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap_err(), "foobar");
+        BOOST_TEST(!result);
+        BOOST_TEST(!result.is_ok());
+        BOOST_TEST(result.is_err());
+        BOOST_TEST(result.unwrap_err() == "foobar");
     }
     {
         const auto f = toml::err<std::string>("foobar");
         toml::result<int, std::string> result(f);
-        BOOST_CHECK(!result);
-        BOOST_CHECK(!result.is_ok());
-        BOOST_CHECK(result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap_err(), "foobar");
+        BOOST_TEST(!result);
+        BOOST_TEST(!result.is_ok());
+        BOOST_TEST(result.is_err());
+        BOOST_TEST(result.unwrap_err() == "foobar");
     }
     {
         toml::result<int, std::string> result(toml::err<std::string>("foobar"));
-        BOOST_CHECK(!result);
-        BOOST_CHECK(!result.is_ok());
-        BOOST_CHECK(result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap_err(), "foobar");
+        BOOST_TEST(!result);
+        BOOST_TEST(!result.is_ok());
+        BOOST_TEST(result.is_err());
+        BOOST_TEST(result.unwrap_err() == "foobar");
     }
 }
 
@@ -59,54 +59,54 @@ BOOST_AUTO_TEST_CASE(test_assignment)
     {
         toml::result<int, std::string> result(toml::err<std::string>("foobar"));
         result = toml::ok(42);
-        BOOST_CHECK(!!result);
-        BOOST_CHECK(result.is_ok());
-        BOOST_CHECK(!result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap(), 42);
+        BOOST_TEST(!!result);
+        BOOST_TEST(result.is_ok());
+        BOOST_TEST(!result.is_err());
+        BOOST_TEST(result.unwrap() == 42);
     }
     {
         toml::result<int, std::string> result(toml::err<std::string>("foobar"));
         auto s = toml::ok(42);
         result = s;
-        BOOST_CHECK(!!result);
-        BOOST_CHECK(result.is_ok());
-        BOOST_CHECK(!result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap(), 42);
+        BOOST_TEST(!!result);
+        BOOST_TEST(result.is_ok());
+        BOOST_TEST(!result.is_err());
+        BOOST_TEST(result.unwrap() == 42);
     }
     {
         toml::result<int, std::string> result(toml::err<std::string>("foobar"));
         const auto s = toml::ok(42);
         result = s;
-        BOOST_CHECK(!!result);
-        BOOST_CHECK(result.is_ok());
-        BOOST_CHECK(!result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap(), 42);
+        BOOST_TEST(!!result);
+        BOOST_TEST(result.is_ok());
+        BOOST_TEST(!result.is_err());
+        BOOST_TEST(result.unwrap() == 42);
     }
     {
         toml::result<int, std::string> result(toml::err<std::string>("foobar"));
         result = toml::err<std::string>("hoge");
-        BOOST_CHECK(!result);
-        BOOST_CHECK(!result.is_ok());
-        BOOST_CHECK(result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap_err(), "hoge");
+        BOOST_TEST(!result);
+        BOOST_TEST(!result.is_ok());
+        BOOST_TEST(result.is_err());
+        BOOST_TEST(result.unwrap_err() == "hoge");
     }
     {
         toml::result<int, std::string> result(toml::err<std::string>("foobar"));
         auto f = toml::err<std::string>("hoge");
         result = f;
-        BOOST_CHECK(!result);
-        BOOST_CHECK(!result.is_ok());
-        BOOST_CHECK(result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap_err(), "hoge");
+        BOOST_TEST(!result);
+        BOOST_TEST(!result.is_ok());
+        BOOST_TEST(result.is_err());
+        BOOST_TEST(result.unwrap_err() == "hoge");
     }
     {
         toml::result<int, std::string> result(toml::err<std::string>("foobar"));
         const auto f = toml::err<std::string>("hoge");
         result = f;
-        BOOST_CHECK(!result);
-        BOOST_CHECK(!result.is_ok());
-        BOOST_CHECK(result.is_err());
-        BOOST_CHECK_EQUAL(result.unwrap_err(), "hoge");
+        BOOST_TEST(!result);
+        BOOST_TEST(!result.is_ok());
+        BOOST_TEST(result.is_err());
+        BOOST_TEST(result.unwrap_err() == "hoge");
     }
 }
 
@@ -119,10 +119,10 @@ BOOST_AUTO_TEST_CASE(test_map)
                     return i * 2;
                 });
 
-        BOOST_CHECK(!!mapped);
-        BOOST_CHECK(mapped.is_ok());
-        BOOST_CHECK(!mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap(), 42 * 2);
+        BOOST_TEST(!!mapped);
+        BOOST_TEST(mapped.is_ok());
+        BOOST_TEST(!mapped.is_err());
+        BOOST_TEST(mapped.unwrap() == 42 * 2);
     }
     {
         toml::result<std::unique_ptr<int>, std::string>
@@ -132,10 +132,10 @@ BOOST_AUTO_TEST_CASE(test_map)
                     return *i;
                 });
 
-        BOOST_CHECK(!!mapped);
-        BOOST_CHECK(mapped.is_ok());
-        BOOST_CHECK(!mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap(), 42);
+        BOOST_TEST(!!mapped);
+        BOOST_TEST(mapped.is_ok());
+        BOOST_TEST(!mapped.is_err());
+        BOOST_TEST(mapped.unwrap() == 42);
     }
     {
         const toml::result<int, std::string> result(toml::err<std::string>("hoge"));
@@ -144,10 +144,10 @@ BOOST_AUTO_TEST_CASE(test_map)
                     return i * 2;
                 });
 
-        BOOST_CHECK(!mapped);
-        BOOST_CHECK(!mapped.is_ok());
-        BOOST_CHECK(mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap_err(), "hoge");
+        BOOST_TEST(!mapped);
+        BOOST_TEST(!mapped.is_ok());
+        BOOST_TEST(mapped.is_err());
+        BOOST_TEST(mapped.unwrap_err() == "hoge");
     }
     {
         toml::result<std::unique_ptr<int>, std::string>
@@ -157,10 +157,10 @@ BOOST_AUTO_TEST_CASE(test_map)
                     return *i;
                 });
 
-        BOOST_CHECK(!mapped);
-        BOOST_CHECK(!mapped.is_ok());
-        BOOST_CHECK(mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap_err(), "hoge");
+        BOOST_TEST(!mapped);
+        BOOST_TEST(!mapped.is_ok());
+        BOOST_TEST(mapped.is_err());
+        BOOST_TEST(mapped.unwrap_err() == "hoge");
     }
 }
 
@@ -173,10 +173,10 @@ BOOST_AUTO_TEST_CASE(test_map_err)
                     return s + s;
                 });
 
-        BOOST_CHECK(!!mapped);
-        BOOST_CHECK(mapped.is_ok());
-        BOOST_CHECK(!mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap(), 42);
+        BOOST_TEST(!!mapped);
+        BOOST_TEST(mapped.is_ok());
+        BOOST_TEST(!mapped.is_err());
+        BOOST_TEST(mapped.unwrap() == 42);
     }
     {
         toml::result<std::unique_ptr<int>, std::string>
@@ -186,10 +186,10 @@ BOOST_AUTO_TEST_CASE(test_map_err)
                     return s + s;
                 });
 
-        BOOST_CHECK(!!mapped);
-        BOOST_CHECK(mapped.is_ok());
-        BOOST_CHECK(!mapped.is_err());
-        BOOST_CHECK_EQUAL(*(mapped.unwrap()), 42);
+        BOOST_TEST(!!mapped);
+        BOOST_TEST(mapped.is_ok());
+        BOOST_TEST(!mapped.is_err());
+        BOOST_TEST(*(mapped.unwrap()) == 42);
     }
     {
         const toml::result<int, std::string> result(toml::err<std::string>("hoge"));
@@ -197,10 +197,10 @@ BOOST_AUTO_TEST_CASE(test_map_err)
                 [](const std::string s) -> std::string {
                     return s + s;
                 });
-        BOOST_CHECK(!mapped);
-        BOOST_CHECK(!mapped.is_ok());
-        BOOST_CHECK(mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap_err(), "hogehoge");
+        BOOST_TEST(!mapped);
+        BOOST_TEST(!mapped.is_ok());
+        BOOST_TEST(mapped.is_err());
+        BOOST_TEST(mapped.unwrap_err() == "hogehoge");
     }
     {
         toml::result<int, std::unique_ptr<std::string>>
@@ -210,10 +210,10 @@ BOOST_AUTO_TEST_CASE(test_map_err)
                     return *p;
                 });
 
-        BOOST_CHECK(!mapped);
-        BOOST_CHECK(!mapped.is_ok());
-        BOOST_CHECK(mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap_err(), "hoge");
+        BOOST_TEST(!mapped);
+        BOOST_TEST(!mapped.is_ok());
+        BOOST_TEST(mapped.is_err());
+        BOOST_TEST(mapped.unwrap_err() == "hoge");
     }
 }
 
@@ -226,7 +226,7 @@ BOOST_AUTO_TEST_CASE(test_map_or_else)
                     return i * 2;
                 }, 54);
 
-        BOOST_CHECK_EQUAL(mapped, 42 * 2);
+        BOOST_TEST(mapped == 42 * 2);
     }
     {
         toml::result<std::unique_ptr<int>, std::string>
@@ -236,7 +236,7 @@ BOOST_AUTO_TEST_CASE(test_map_or_else)
                     return *i;
                 }, 54);
 
-        BOOST_CHECK_EQUAL(mapped, 42);
+        BOOST_TEST(mapped == 42);
     }
     {
         const toml::result<int, std::string> result(toml::err<std::string>("hoge"));
@@ -245,7 +245,7 @@ BOOST_AUTO_TEST_CASE(test_map_or_else)
                     return i * 2;
                 }, 54);
 
-        BOOST_CHECK_EQUAL(mapped, 54);
+        BOOST_TEST(mapped == 54);
     }
     {
         toml::result<std::unique_ptr<int>, std::string>
@@ -255,7 +255,7 @@ BOOST_AUTO_TEST_CASE(test_map_or_else)
                     return *i;
                 }, 54);
 
-        BOOST_CHECK_EQUAL(mapped, 54);
+        BOOST_TEST(mapped == 54);
     }
 }
 
@@ -268,7 +268,7 @@ BOOST_AUTO_TEST_CASE(test_map_err_or_else)
                     return i + i;
                 }, "foobar");
 
-        BOOST_CHECK_EQUAL(mapped, "foobar");
+        BOOST_TEST(mapped == "foobar");
     }
     {
         toml::result<std::unique_ptr<int>, std::string>
@@ -278,7 +278,7 @@ BOOST_AUTO_TEST_CASE(test_map_err_or_else)
                     return i + i;
                 }, "foobar");
 
-        BOOST_CHECK_EQUAL(mapped, "foobar");
+        BOOST_TEST(mapped == "foobar");
     }
     {
         const toml::result<int, std::string> result(toml::err<std::string>("hoge"));
@@ -287,7 +287,7 @@ BOOST_AUTO_TEST_CASE(test_map_err_or_else)
                     return i + i;
                 }, "foobar");
 
-        BOOST_CHECK_EQUAL(mapped, "hogehoge");
+        BOOST_TEST(mapped == "hogehoge");
     }
     {
         toml::result<std::unique_ptr<int>, std::string>
@@ -297,7 +297,7 @@ BOOST_AUTO_TEST_CASE(test_map_err_or_else)
                     return i + i;
                 }, "foobar");
 
-        BOOST_CHECK_EQUAL(mapped, "hogehoge");
+        BOOST_TEST(mapped == "hogehoge");
     }
 }
 
@@ -311,10 +311,10 @@ BOOST_AUTO_TEST_CASE(test_and_then)
                     return toml::ok(i * 2);
                 });
 
-        BOOST_CHECK(!!mapped);
-        BOOST_CHECK(mapped.is_ok());
-        BOOST_CHECK(!mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap(), 42 * 2);
+        BOOST_TEST(!!mapped);
+        BOOST_TEST(mapped.is_ok());
+        BOOST_TEST(!mapped.is_err());
+        BOOST_TEST(mapped.unwrap() == 42 * 2);
     }
     {
         toml::result<std::unique_ptr<int>, std::string>
@@ -324,10 +324,10 @@ BOOST_AUTO_TEST_CASE(test_and_then)
                     return toml::ok(*i);
                 });
 
-        BOOST_CHECK(!!mapped);
-        BOOST_CHECK(mapped.is_ok());
-        BOOST_CHECK(!mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap(), 42);
+        BOOST_TEST(!!mapped);
+        BOOST_TEST(mapped.is_ok());
+        BOOST_TEST(!mapped.is_err());
+        BOOST_TEST(mapped.unwrap() == 42);
     }
     {
         const toml::result<int, std::string> result(toml::err<std::string>("hoge"));
@@ -336,10 +336,10 @@ BOOST_AUTO_TEST_CASE(test_and_then)
                     return toml::ok(i * 2);
                 });
 
-        BOOST_CHECK(!mapped);
-        BOOST_CHECK(!mapped.is_ok());
-        BOOST_CHECK(mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap_err(), "hoge");
+        BOOST_TEST(!mapped);
+        BOOST_TEST(!mapped.is_ok());
+        BOOST_TEST(mapped.is_err());
+        BOOST_TEST(mapped.unwrap_err() == "hoge");
     }
     {
         toml::result<std::unique_ptr<int>, std::string>
@@ -349,10 +349,10 @@ BOOST_AUTO_TEST_CASE(test_and_then)
                     return toml::ok(*i);
                 });
 
-        BOOST_CHECK(!mapped);
-        BOOST_CHECK(!mapped.is_ok());
-        BOOST_CHECK(mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap_err(), "hoge");
+        BOOST_TEST(!mapped);
+        BOOST_TEST(!mapped.is_ok());
+        BOOST_TEST(mapped.is_err());
+        BOOST_TEST(mapped.unwrap_err() == "hoge");
     }
 }
 
@@ -365,10 +365,10 @@ BOOST_AUTO_TEST_CASE(test_or_else)
                     return toml::err(s + s);
                 });
 
-        BOOST_CHECK(!!mapped);
-        BOOST_CHECK(mapped.is_ok());
-        BOOST_CHECK(!mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap(), 42);
+        BOOST_TEST(!!mapped);
+        BOOST_TEST(mapped.is_ok());
+        BOOST_TEST(!mapped.is_err());
+        BOOST_TEST(mapped.unwrap() == 42);
     }
     {
         toml::result<std::unique_ptr<int>, std::string>
@@ -378,10 +378,10 @@ BOOST_AUTO_TEST_CASE(test_or_else)
                     return toml::err(s + s);
                 });
 
-        BOOST_CHECK(!!mapped);
-        BOOST_CHECK(mapped.is_ok());
-        BOOST_CHECK(!mapped.is_err());
-        BOOST_CHECK_EQUAL(*mapped.unwrap(), 42);
+        BOOST_TEST(!!mapped);
+        BOOST_TEST(mapped.is_ok());
+        BOOST_TEST(!mapped.is_err());
+        BOOST_TEST(*mapped.unwrap() == 42);
     }
     {
         const toml::result<int, std::string> result(toml::err<std::string>("hoge"));
@@ -390,10 +390,10 @@ BOOST_AUTO_TEST_CASE(test_or_else)
                     return toml::err(s + s);
                 });
 
-        BOOST_CHECK(!mapped);
-        BOOST_CHECK(!mapped.is_ok());
-        BOOST_CHECK(mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap_err(), "hogehoge");
+        BOOST_TEST(!mapped);
+        BOOST_TEST(!mapped.is_ok());
+        BOOST_TEST(mapped.is_err());
+        BOOST_TEST(mapped.unwrap_err() == "hogehoge");
     }
     {
         toml::result<std::unique_ptr<int>, std::string>
@@ -403,10 +403,10 @@ BOOST_AUTO_TEST_CASE(test_or_else)
                     return toml::err(s + s);
                 });
 
-        BOOST_CHECK(!mapped);
-        BOOST_CHECK(!mapped.is_ok());
-        BOOST_CHECK(mapped.is_err());
-        BOOST_CHECK_EQUAL(mapped.unwrap_err(), "hogehoge");
+        BOOST_TEST(!mapped);
+        BOOST_TEST(!mapped.is_ok());
+        BOOST_TEST(mapped.is_err());
+        BOOST_TEST(mapped.unwrap_err() == "hogehoge");
     }
 }
 
@@ -416,10 +416,10 @@ BOOST_AUTO_TEST_CASE(test_and_or_other)
         const toml::result<int, std::string> r1(toml::ok(42));
         const toml::result<int, std::string> r2(toml::err<std::string>("foo"));
 
-        BOOST_CHECK_EQUAL(r1,    r1.or_other(r2));
-        BOOST_CHECK_EQUAL(r2,    r1.and_other(r2));
-        BOOST_CHECK_EQUAL(42,    r1.or_other(r2).unwrap());
-        BOOST_CHECK_EQUAL("foo", r1.and_other(r2).unwrap_err());
+        BOOST_TEST(r1 ==    r1.or_other(r2));
+        BOOST_TEST(r2 ==    r1.and_other(r2));
+        BOOST_TEST(42 ==    r1.or_other(r2).unwrap());
+        BOOST_TEST("foo" == r1.and_other(r2).unwrap_err());
     }
     {
         auto r1_gen = []() -> toml::result<int, std::string> {
@@ -431,10 +431,10 @@ BOOST_AUTO_TEST_CASE(test_and_or_other)
         const auto r3 = r1_gen();
         const auto r4 = r2_gen();
 
-        BOOST_CHECK_EQUAL(r3, r1_gen().or_other (r2_gen()));
-        BOOST_CHECK_EQUAL(r4, r1_gen().and_other(r2_gen()));
-        BOOST_CHECK_EQUAL(42,    r1_gen().or_other (r2_gen()).unwrap());
-        BOOST_CHECK_EQUAL("foo", r1_gen().and_other(r2_gen()).unwrap_err());
+        BOOST_TEST(r3 == r1_gen().or_other (r2_gen()));
+        BOOST_TEST(r4 == r1_gen().and_other(r2_gen()));
+        BOOST_TEST(42 ==    r1_gen().or_other (r2_gen()).unwrap());
+        BOOST_TEST("foo" == r1_gen().and_other(r2_gen()).unwrap_err());
     }
 }
 

tests/test_serialize_file.cpp

@@ -6,9 +6,44 @@
 #include <boost/test/included/unit_test.hpp>
 #endif
 #include <toml.hpp>
+#include <deque>
+#include <map>
 #include <iostream>
 #include <fstream>
+#include <sstream>
 
+template<typename Comment,
+         template<typename ...> class Table,
+         template<typename ...> class Array>
+bool has_comment_inside(const toml::basic_value<Comment, Table, Array>& v)
+{
+    if(!v.comments().empty())
+    {
+        return false;
+    }
+    // v itself does not have a comment.
+    if(v.is_array())
+    {
+        for(const auto& x : v.as_array())
+        {
+            if(has_comment_inside(x))
+            {
+                return false;
+            }
+        }
+    }
+    if(v.is_table())
+    {
+        for(const auto& x : v.as_table())
+        {
+            if(has_comment_inside(x.second))
+            {
+                return false;
+            }
+        }
+    }
+    return true;
+}
 
 BOOST_AUTO_TEST_CASE(test_example)
 {
@@ -20,15 +55,146 @@ BOOST_AUTO_TEST_CASE(test_example)
 
     auto serialized = toml::parse("tmp1.toml");
     {
-        auto& owner = toml::get<toml::table>(serialized.at("owner"));
-        auto& bio   = toml::get<std::string>(owner.at("bio"));
+        auto& owner = toml::find(serialized, "owner");
+        auto& bio   = toml::find<std::string>(owner, "bio");
         const auto CR = std::find(bio.begin(), bio.end(), '\r');
         if(CR != bio.end())
         {
             bio.erase(CR);
         }
     }
-    BOOST_CHECK(data == serialized);
+    BOOST_TEST(data == serialized);
+}
+
+BOOST_AUTO_TEST_CASE(test_example_map_dq)
+{
+    const auto data = toml::parse<toml::discard_comments, std::map, std::deque>(
+            "toml/tests/example.toml");
+    {
+        std::ofstream ofs("tmp1_map_dq.toml");
+        ofs << std::setw(80) << data;
+    }
+
+    auto serialized = toml::parse<toml::discard_comments, std::map, std::deque>(
+            "tmp1_map_dq.toml");
+    {
+        auto& owner = toml::find(serialized, "owner");
+        auto& bio   = toml::find<std::string>(owner, "bio");
+        const auto CR = std::find(bio.begin(), bio.end(), '\r');
+        if(CR != bio.end())
+        {
+            bio.erase(CR);
+        }
+    }
+    BOOST_TEST(data == serialized);
+}
+
+BOOST_AUTO_TEST_CASE(test_example_with_comment)
+{
+    const auto data = toml::parse<toml::preserve_comments>("toml/tests/example.toml");
+    {
+        std::ofstream ofs("tmp1_com.toml");
+        ofs << std::setw(80) << data;
+    }
+
+    auto serialized = toml::parse<toml::preserve_comments>("tmp1_com.toml");
+    {
+        auto& owner = toml::find(serialized, "owner");
+        auto& bio   = toml::find<std::string>(owner, "bio");
+        const auto CR = std::find(bio.begin(), bio.end(), '\r');
+        if(CR != bio.end())
+        {
+            bio.erase(CR);
+        }
+    }
+    BOOST_TEST(data == serialized);
+    {
+        std::ofstream ofs("tmp1_com1.toml");
+        ofs << std::setw(80) << serialized;
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_example_with_comment_nocomment)
+{
+    {
+        const auto data = toml::parse<toml::preserve_comments>("toml/tests/example.toml");
+        {
+            std::ofstream ofs("tmp1_com_nocomment.toml");
+            ofs << std::setw(80) << toml::nocomment << data;
+        }
+        const auto serialized = toml::parse<toml::preserve_comments>("tmp1_com_nocomment.toml");
+        // check no comment exist
+        BOOST_TEST(!has_comment_inside(serialized));
+    }
+    {
+        const auto data_nocomment = toml::parse("toml/tests/example.toml");
+        auto serialized = toml::parse("tmp1_com_nocomment.toml");
+        {
+            auto& owner = toml::find(serialized, "owner");
+            auto& bio   = toml::find<std::string>(owner, "bio");
+            const auto CR = std::find(bio.begin(), bio.end(), '\r');
+            if(CR != bio.end())
+            {
+                bio.erase(CR);
+            }
+        }
+        // check collectly serialized
+        BOOST_TEST(data_nocomment == serialized);
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_example_with_comment_map_dq)
+{
+    const auto data = toml::parse<toml::preserve_comments, std::map, std::deque>(
+            "toml/tests/example.toml");
+    {
+        std::ofstream ofs("tmp1_com_map_dq.toml");
+        ofs << std::setw(80) << data;
+    }
+
+    auto serialized = toml::parse<toml::preserve_comments, std::map, std::deque>(
+            "tmp1_com_map_dq.toml");
+    {
+        auto& owner = toml::find(serialized, "owner");
+        auto& bio   = toml::find<std::string>(owner, "bio");
+        const auto CR = std::find(bio.begin(), bio.end(), '\r');
+        if(CR != bio.end())
+        {
+            bio.erase(CR);
+        }
+    }
+    BOOST_TEST(data == serialized);
+    {
+        std::ofstream ofs("tmp1_com1_map_dq.toml");
+        ofs << std::setw(80) << serialized;
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_example_with_comment_map_dq_nocomment)
+{
+    {
+        const auto data = toml::parse<toml::preserve_comments, std::map, std::deque>("toml/tests/example.toml");
+        {
+            std::ofstream ofs("tmp1_com_map_dq_nocomment.toml");
+            ofs << std::setw(80) << toml::nocomment << data;
+        }
+        const auto serialized = toml::parse<toml::preserve_comments, std::map, std::deque>("tmp1_com_map_dq_nocomment.toml");
+        BOOST_TEST(!has_comment_inside(serialized));
+    }
+    {
+        const auto data_nocomment = toml::parse("toml/tests/example.toml");
+        auto serialized = toml::parse("tmp1_com_map_dq_nocomment.toml");
+        {
+            auto& owner = toml::find(serialized, "owner");
+            auto& bio   = toml::find<std::string>(owner, "bio");
+            const auto CR = std::find(bio.begin(), bio.end(), '\r');
+            if(CR != bio.end())
+            {
+                bio.erase(CR);
+            }
+        }
+        BOOST_TEST(data_nocomment == serialized);
+    }
 }
 
 BOOST_AUTO_TEST_CASE(test_fruit)
@@ -39,7 +205,43 @@ BOOST_AUTO_TEST_CASE(test_fruit)
         ofs << std::setw(80) << data;
     }
     const auto serialized = toml::parse("tmp2.toml");
-    BOOST_CHECK(data == serialized);
+    BOOST_TEST(data == serialized);
+}
+
+BOOST_AUTO_TEST_CASE(test_fruit_map_dq)
+{
+    const auto data = toml::parse<toml::discard_comments, std::map, std::deque>(
+            "toml/tests/fruit.toml");
+    {
+        std::ofstream ofs("tmp2.toml");
+        ofs << std::setw(80) << data;
+    }
+    const auto serialized = toml::parse<toml::discard_comments, std::map, std::deque>(
+            "tmp2.toml");
+    BOOST_TEST(data == serialized);
+}
+
+BOOST_AUTO_TEST_CASE(test_fruit_with_comments)
+{
+    const auto data = toml::parse<toml::preserve_comments>("toml/tests/fruit.toml");
+    {
+        std::ofstream ofs("tmp2_com.toml");
+        ofs << std::setw(80) << data;
+    }
+    const auto serialized = toml::parse<toml::preserve_comments>("tmp2_com.toml");
+    BOOST_TEST(data == serialized);
+}
+
+BOOST_AUTO_TEST_CASE(test_fruit_with_comments_map_dq)
+{
+    const auto data = toml::parse<toml::preserve_comments, std::map, std::deque>(
+        "toml/tests/fruit.toml");
+    {
+        std::ofstream ofs("tmp2_com.toml");
+        ofs << std::setw(80) << data;
+    }
+    const auto serialized = toml::parse<toml::preserve_comments, std::map, std::deque>("tmp2_com.toml");
+    BOOST_TEST(data == serialized);
 }
 
 BOOST_AUTO_TEST_CASE(test_hard_example)
@@ -50,5 +252,112 @@ BOOST_AUTO_TEST_CASE(test_hard_example)
         ofs << std::setw(80) << data;
     }
     const auto serialized = toml::parse("tmp3.toml");
-    BOOST_CHECK(data == serialized);
+    BOOST_TEST(data == serialized);
+}
+
+BOOST_AUTO_TEST_CASE(test_hard_example_map_dq)
+{
+    const auto data = toml::parse<toml::discard_comments, std::map, std::deque>(
+            "toml/tests/hard_example.toml");
+    {
+        std::ofstream ofs("tmp3.toml");
+        ofs << std::setw(80) << data;
+    }
+    const auto serialized = toml::parse<toml::discard_comments, std::map, std::deque>(
+            "tmp3.toml");
+    BOOST_TEST(data == serialized);
+}
+
+BOOST_AUTO_TEST_CASE(test_hard_example_with_comment)
+{
+    const auto data = toml::parse<toml::preserve_comments, std::map, std::deque>(
+            "toml/tests/hard_example.toml");
+    {
+        std::ofstream ofs("tmp3_com.toml");
+        ofs << std::setw(80) << data;
+    }
+    const auto serialized = toml::parse<toml::preserve_comments, std::map, std::deque>(
+            "tmp3_com.toml");
+    {
+        std::ofstream ofs("tmp3_com1.toml");
+        ofs << std::setw(80) << serialized;
+    }
+    BOOST_TEST(data == serialized);
+}
+
+BOOST_AUTO_TEST_CASE(test_format_key)
+{
+    {
+        const toml::key key("normal_bare-key");
+        BOOST_TEST("normal_bare-key" == toml::format_key(key));
+    }
+    {
+        const toml::key key("key.include.dots");
+        BOOST_TEST("\"key.include.dots\"" == toml::format_key(key));
+    }
+    {
+        const toml::key key("key-include-unicode-\xE3\x81\x82");
+        BOOST_TEST("\"key-include-unicode-\xE3\x81\x82\"" == toml::format_key(key));
+    }
+    {
+        const toml::key key("special-chars-\\-\"-\b-\f-\r-\n-\t");
+        BOOST_TEST("\"special-chars-\\\\-\\\"-\\b-\\f-\\r-\\n-\\t\"" == toml::format_key(key));
+    }
+}
+
+// In toml11, an implicitly-defined value does not have any comments.
+// So, in the following file,
+// ```toml
+// # comment
+// [[array-of-tables]]
+// foo = "bar"
+// ```
+// The array named "array-of-tables" does not have the comment, but the first
+// element of the array has. That means that, the above file is equivalent to
+// the following.
+// ```toml
+// array-of-tables = [
+//     # comment
+//     {foo = "bar"},
+// ]
+// ```
+// If the array itself has a comment (value_has_comment_ == true), we should try
+// to make it inline.
+// ```toml
+// # comment about array
+// array-of-tables = [
+//   # comment about table element
+//   {foo = "bar"}
+// ]
+// ```
+// If it is formatted as a multiline table, the two comments becomes
+// indistinguishable.
+// ```toml
+// # comment about array
+// # comment about table element
+// [[array-of-tables]]
+// foo = "bar"
+// ```
+// So we need to try to make it inline, and it force-inlines regardless
+// of the line width limit.
+//     It may fail if the element of a table has comment. In that case,
+// the array-of-tables will be formatted as a multiline table.
+BOOST_AUTO_TEST_CASE(test_distinguish_comment)
+{
+    const std::string str = R"(# comment about array itself
+array_of_table = [
+    # comment about the first element (table)
+    {key = "value"},
+])";
+    std::istringstream iss(str);
+    const auto data = toml::parse<toml::preserve_comments>(iss);
+    const auto serialized = toml::format(data, /*width = */ 0);
+
+    std::istringstream reparse(serialized);
+    const auto parsed = toml::parse<toml::preserve_comments>(reparse);
+
+    BOOST_TEST(parsed.at("array_of_table").comments().size()  == 1u);
+    BOOST_TEST(parsed.at("array_of_table").comments().front() == " comment about array itself");
+    BOOST_TEST(parsed.at("array_of_table").at(0).comments().size()  == 1u);
+    BOOST_TEST(parsed.at("array_of_table").at(0).comments().front() == " comment about the first element (table)");
 }

tests/test_string.cpp

@@ -0,0 +1,154 @@
+#define BOOST_TEST_MODULE "test_string"
+#include <boost/test/unit_test.hpp>
+#include <toml.hpp>
+
+BOOST_AUTO_TEST_CASE(test_basic_string)
+{
+    {
+        const toml::string str("basic string");
+        std::ostringstream oss;
+        oss << str;
+        BOOST_TEST(oss.str() == "\"basic string\"");
+    }
+    {
+        const std::string  s1 ("basic string");
+        const toml::string str(s1);
+        std::ostringstream oss;
+        oss << str;
+        BOOST_TEST(oss.str() == "\"basic string\"");
+    }
+    {
+        const toml::string str("basic string", toml::string_t::basic);
+        std::ostringstream oss;
+        oss << str;
+        BOOST_TEST(oss.str() == "\"basic string\"");
+    }
+    {
+        const std::string  s1 ("basic string");
+        const toml::string str(s1, toml::string_t::basic);
+        std::ostringstream oss;
+        oss << str;
+        BOOST_TEST(oss.str() == "\"basic string\"");
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_basic_ml_string)
+{
+    {
+        const toml::string str("basic\nstring");
+        std::ostringstream oss1;
+        oss1 << str;
+        std::ostringstream oss2;
+        oss2 << "\"\"\"\nbasic\nstring\\\n\"\"\"";
+        BOOST_TEST(oss1.str() == oss2.str());
+    }
+    {
+        const std::string  s1 ("basic\nstring");
+        const toml::string str(s1);
+        std::ostringstream oss1;
+        oss1 << str;
+        std::ostringstream oss2;
+        oss2 << "\"\"\"\nbasic\nstring\\\n\"\"\"";
+        BOOST_TEST(oss1.str() == oss2.str());
+    }
+    {
+        const toml::string str("basic\nstring", toml::string_t::basic);
+        std::ostringstream oss1;
+        oss1 << str;
+        std::ostringstream oss2;
+        oss2 << "\"\"\"\nbasic\nstring\\\n\"\"\"";
+        BOOST_TEST(oss1.str() == oss2.str());
+
+    }
+    {
+        const std::string  s1 ("basic\nstring");
+        const toml::string str(s1, toml::string_t::basic);
+        std::ostringstream oss1;
+        oss1 << str;
+        std::ostringstream oss2;
+        oss2 << "\"\"\"\nbasic\nstring\\\n\"\"\"";
+        BOOST_TEST(oss1.str() == oss2.str());
+    }
+}
+
+
+BOOST_AUTO_TEST_CASE(test_literal_string)
+{
+    {
+        const toml::string str("literal string", toml::string_t::literal);
+        std::ostringstream oss;
+        oss << str;
+        BOOST_TEST(oss.str() == "'literal string'");
+    }
+    {
+        const std::string  s1 ("literal string");
+        const toml::string str(s1, toml::string_t::literal);
+        std::ostringstream oss;
+        oss << str;
+        BOOST_TEST(oss.str() == "'literal string'");
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_literal_ml_string)
+{
+    {
+        const toml::string str("literal\nstring", toml::string_t::literal);
+        std::ostringstream oss1;
+        oss1 << str;
+        std::ostringstream oss2;
+        oss2 << "'''\nliteral\nstring'''";
+        BOOST_TEST(oss1.str() == oss2.str());
+
+    }
+    {
+        const std::string  s1 ("literal\nstring");
+        const toml::string str(s1, toml::string_t::literal);
+        std::ostringstream oss1;
+        oss1 << str;
+        std::ostringstream oss2;
+        oss2 << "'''\nliteral\nstring'''";
+        BOOST_TEST(oss1.str() == oss2.str());
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_string_add_assign)
+{
+    // string literal
+    {
+        toml::string str("foo");
+        str += "bar";
+        BOOST_TEST(str.str == "foobar");
+    }
+    // std::string
+    {
+        toml::string str("foo");
+        std::string str2("bar");
+        str += str2;
+        BOOST_TEST(str.str == "foobar");
+    }
+    // toml::string
+    {
+        toml::string str("foo");
+        toml::string str2("bar");
+        str += str2;
+        BOOST_TEST(str.str == "foobar");
+    }
+#if __cplusplus >= 201703L
+    // std::string_view
+    {
+        toml::string str("foo");
+        str += std::string_view("bar");
+        BOOST_TEST(str == "foobar");
+    }
+#endif
+    // std::string += toml::string
+    {
+        std::string  str("foo");
+        toml::string str2("bar");
+        str += str2;
+        BOOST_TEST(str == "foobar");
+    }
+
+
+}
+

tests/test_traits.cpp

@@ -37,48 +37,48 @@ typedef std::unordered_map<std::string, dummy_type> std_unordered_map_type;
 
 BOOST_AUTO_TEST_CASE(test_has_xxx)
 {
-    BOOST_CHECK(toml::detail::has_iterator<std::list<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::has_iterator<std::forward_list<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::has_iterator<std::deque<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::has_iterator<std::vector<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::has_iterator<std::set<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::has_iterator<std::unordered_set<std::string>>::value);
-    BOOST_CHECK(toml::detail::has_iterator<std_array_type>::value);
-    BOOST_CHECK(toml::detail::has_iterator<std_map_type>::value);
-    BOOST_CHECK(toml::detail::has_iterator<std_unordered_map_type>::value);
-    BOOST_CHECK(toml::detail::has_iterator<dummy_container<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_iterator<std::list<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_iterator<std::forward_list<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_iterator<std::deque<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_iterator<std::vector<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_iterator<std::set<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_iterator<std::unordered_set<std::string>>::value);
+    BOOST_TEST(toml::detail::has_iterator<std_array_type>::value);
+    BOOST_TEST(toml::detail::has_iterator<std_map_type>::value);
+    BOOST_TEST(toml::detail::has_iterator<std_unordered_map_type>::value);
+    BOOST_TEST(toml::detail::has_iterator<dummy_container<dummy_type>>::value);
 
-    BOOST_CHECK(toml::detail::has_value_type<std::list<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::has_value_type<std::forward_list<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::has_value_type<std::deque<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::has_value_type<std::vector<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::has_value_type<std_array_type>::value);
-    BOOST_CHECK(toml::detail::has_value_type<std::set<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::has_value_type<std::unordered_set<std::string>>::value);
-    BOOST_CHECK(toml::detail::has_value_type<std_map_type>::value);
-    BOOST_CHECK(toml::detail::has_value_type<std_unordered_map_type>::value);
-    BOOST_CHECK(toml::detail::has_value_type<dummy_container<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_value_type<std::list<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_value_type<std::forward_list<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_value_type<std::deque<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_value_type<std::vector<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_value_type<std_array_type>::value);
+    BOOST_TEST(toml::detail::has_value_type<std::set<dummy_type>>::value);
+    BOOST_TEST(toml::detail::has_value_type<std::unordered_set<std::string>>::value);
+    BOOST_TEST(toml::detail::has_value_type<std_map_type>::value);
+    BOOST_TEST(toml::detail::has_value_type<std_unordered_map_type>::value);
+    BOOST_TEST(toml::detail::has_value_type<dummy_container<dummy_type>>::value);
 
-    BOOST_CHECK(toml::detail::has_key_type<std_map_type>::value);
-    BOOST_CHECK(toml::detail::has_key_type<std_unordered_map_type>::value);
-    BOOST_CHECK(toml::detail::has_mapped_type<std_map_type>::value);
-    BOOST_CHECK(toml::detail::has_mapped_type<std_unordered_map_type>::value);
+    BOOST_TEST(toml::detail::has_key_type<std_map_type>::value);
+    BOOST_TEST(toml::detail::has_key_type<std_unordered_map_type>::value);
+    BOOST_TEST(toml::detail::has_mapped_type<std_map_type>::value);
+    BOOST_TEST(toml::detail::has_mapped_type<std_unordered_map_type>::value);
 }
 
 BOOST_AUTO_TEST_CASE(test_is_xxx)
 {
-    BOOST_CHECK(toml::detail::is_container<std::list<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::is_container<std::forward_list<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::is_container<std::deque<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::is_container<std::vector<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::is_container<std_array_type>::value);
-    BOOST_CHECK(toml::detail::is_container<std::set<dummy_type>>::value);
-    BOOST_CHECK(toml::detail::is_container<std::unordered_set<std::string>>::value);
-    BOOST_CHECK(toml::detail::is_container<dummy_container<dummy_type>>::value);
+    BOOST_TEST(toml::detail::is_container<std::list<dummy_type>>::value);
+    BOOST_TEST(toml::detail::is_container<std::forward_list<dummy_type>>::value);
+    BOOST_TEST(toml::detail::is_container<std::deque<dummy_type>>::value);
+    BOOST_TEST(toml::detail::is_container<std::vector<dummy_type>>::value);
+    BOOST_TEST(toml::detail::is_container<std_array_type>::value);
+    BOOST_TEST(toml::detail::is_container<std::set<dummy_type>>::value);
+    BOOST_TEST(toml::detail::is_container<std::unordered_set<std::string>>::value);
+    BOOST_TEST(toml::detail::is_container<dummy_container<dummy_type>>::value);
 
-    BOOST_CHECK(!toml::detail::is_container<std_map_type>::value);
-    BOOST_CHECK(!toml::detail::is_container<std_unordered_map_type>::value);
+    BOOST_TEST(!toml::detail::is_container<std_map_type>::value);
+    BOOST_TEST(!toml::detail::is_container<std_unordered_map_type>::value);
 
-    BOOST_CHECK(toml::detail::is_map<std_map_type>::value);
-    BOOST_CHECK(toml::detail::is_map<std_unordered_map_type>::value);
+    BOOST_TEST(toml::detail::is_map<std_map_type>::value);
+    BOOST_TEST(toml::detail::is_map<std_unordered_map_type>::value);
 }

tests/test_utility.cpp

@@ -9,74 +9,41 @@
 #include <vector>
 #include <array>
 
-BOOST_AUTO_TEST_CASE(test_resize)
+BOOST_AUTO_TEST_CASE(test_try_reserve)
 {
     {
-        typedef std::vector<int>  resizable_type;
-        typedef std::array<int,1> non_resizable_type;
-        BOOST_CHECK(toml::detail::has_resize_method<resizable_type>::value);
-        BOOST_CHECK(!toml::detail::has_resize_method<non_resizable_type>::value);
+        // since BOOST_TEST is a macro, it cannot handle commas correctly.
+        // When toml::detail::has_reserve_method<std::array<int, 1>>::value
+        // is passed to a macro, C preprocessor considers
+        // toml::detail::has_reserve_method<std::array<int as the first argument
+        // and 1>>::value as the second argument. We need an alias to avoid
+        // this problem.
+        using reservable_type    = std::vector<int>  ;
+        using nonreservable_type = std::array<int, 1>;
+        BOOST_TEST( toml::detail::has_reserve_method<reservable_type   >::value);
+        BOOST_TEST(!toml::detail::has_reserve_method<nonreservable_type>::value);
     }
-
     {
-        bool thrown = false;
         std::vector<int> v;
-        try
-        {
-            toml::resize(v, 10);
-        }
-        catch(std::exception& ex)
-        {
-            thrown = true;
-        }
-        BOOST_CHECK(!thrown);
-        BOOST_CHECK_EQUAL(v.size(), 10u);
-    }
-
-    {
-        bool thrown = false;
-        std::array<int, 15> a;
-        try
-        {
-            toml::resize(a, 10);
-        }
-        catch(std::exception& ex)
-        {
-            thrown = true;
-        }
-        BOOST_CHECK(!thrown);
-        BOOST_CHECK_EQUAL(a.size(), 15u);
-    }
-
-    {
-        bool thrown = false;
-        std::array<int, 15> a;
-        try
-        {
-            toml::resize(a, 20);
-        }
-        catch(std::exception& ex)
-        {
-            thrown = true;
-        }
-        BOOST_CHECK(thrown);
+        toml::try_reserve(v, 100);
+        BOOST_TEST(v.capacity() == 100u);
     }
 }
 
 BOOST_AUTO_TEST_CASE(test_concat_to_string)
 {
     const std::string cat = toml::concat_to_string("foo", "bar", 42);
-    BOOST_CHECK(cat == "foobar42");
+    BOOST_TEST(cat == "foobar42");
 }
 
 BOOST_AUTO_TEST_CASE(test_from_string)
 {
     {
         const std::string str("123");
-        BOOST_CHECK_EQUAL(toml::from_string<int>(str, 0), 123);
+        BOOST_TEST(toml::from_string<int>(str, 0) == 123);
     }
     {
         const std::string str("01");
-        BOOST_CHECK_EQUAL(toml::from_string<int>(str, 0), 1);
+        BOOST_TEST(toml::from_string<int>(str, 0) == 1);
     }
 }

tests/test_windows.cpp

@@ -0,0 +1,12 @@
+#include <windows.h>
+#include <toml.hpp>
+#include <iostream>
+
+int main()
+{
+    using namespace toml::literals::toml_literals;
+    const auto data = R"(windows = "defines min and max as a macro")"_toml;
+
+    std::cout << toml::find<std::string>(data, "windows") << std::endl;
+    return 0;
+}

toml.hpp

@@ -33,10 +33,13 @@
 #    error "toml11 requires C++11 or later."
 #endif
 
+#define TOML11_VERSION_MAJOR 3
+#define TOML11_VERSION_MINOR 6
+#define TOML11_VERSION_PATCH 1
+
 #include "toml/parser.hpp"
 #include "toml/literal.hpp"
 #include "toml/serializer.hpp"
-#include "toml/from_toml.hpp"
 #include "toml/get.hpp"
 
 #endif// TOML_FOR_MODERN_CPP

toml/color.hpp

@@ -0,0 +1,64 @@
+#ifndef TOML11_COLOR_HPP
+#define TOML11_COLOR_HPP
+#include <cstdint>
+#include <ostream>
+
+#ifdef TOML11_COLORIZE_ERROR_MESSAGE
+#define TOML11_ERROR_MESSAGE_COLORIZED true
+#else
+#define TOML11_ERROR_MESSAGE_COLORIZED false
+#endif
+
+namespace toml
+{
+
+// put ANSI escape sequence to ostream
+namespace color_ansi
+{
+namespace detail
+{
+inline int colorize_index()
+{
+    static const int index = std::ios_base::xalloc();
+    return index;
+}
+} // detail
+
+inline std::ostream& colorize(std::ostream& os)
+{
+    // by default, it is zero.
+    os.iword(detail::colorize_index()) = 1;
+    return os;
+}
+inline std::ostream& nocolorize(std::ostream& os)
+{
+    os.iword(detail::colorize_index()) = 0;
+    return os;
+}
+inline std::ostream& reset  (std::ostream& os)
+{if(os.iword(detail::colorize_index()) == 1) {os << "\033[00m";} return os;}
+inline std::ostream& bold   (std::ostream& os)
+{if(os.iword(detail::colorize_index()) == 1) {os << "\033[01m";} return os;}
+inline std::ostream& grey   (std::ostream& os)
+{if(os.iword(detail::colorize_index()) == 1) {os << "\033[30m";} return os;}
+inline std::ostream& red    (std::ostream& os)
+{if(os.iword(detail::colorize_index()) == 1) {os << "\033[31m";} return os;}
+inline std::ostream& green  (std::ostream& os)
+{if(os.iword(detail::colorize_index()) == 1) {os << "\033[32m";} return os;}
+inline std::ostream& yellow (std::ostream& os)
+{if(os.iword(detail::colorize_index()) == 1) {os << "\033[33m";} return os;}
+inline std::ostream& blue   (std::ostream& os)
+{if(os.iword(detail::colorize_index()) == 1) {os << "\033[34m";} return os;}
+inline std::ostream& magenta(std::ostream& os)
+{if(os.iword(detail::colorize_index()) == 1) {os << "\033[35m";} return os;}
+inline std::ostream& cyan   (std::ostream& os)
+{if(os.iword(detail::colorize_index()) == 1) {os << "\033[36m";} return os;}
+inline std::ostream& white  (std::ostream& os)
+{if(os.iword(detail::colorize_index()) == 1) {os << "\033[37m";} return os;}
+} // color_ansi
+
+// ANSI escape sequence is the only and default colorization method currently
+namespace color = color_ansi;
+
+} // toml
+#endif// TOML11_COLOR_HPP

toml/combinator.hpp

@@ -2,18 +2,20 @@
 // Distributed under the MIT License.
 #ifndef TOML11_COMBINATOR_HPP
 #define TOML11_COMBINATOR_HPP
-#include "traits.hpp"
-#include "result.hpp"
-#include "utility.hpp"
-#include "region.hpp"
-#include <type_traits>
-#include <iterator>
-#include <limits>
-#include <array>
-#include <iomanip>
-#include <cstdio>
 #include <cassert>
 #include <cctype>
+#include <cstdio>
+
+#include <array>
+#include <iomanip>
+#include <iterator>
+#include <limits>
+#include <type_traits>
+
+#include "region.hpp"
+#include "result.hpp"
+#include "traits.hpp"
+#include "utility.hpp"
 
 // they scans characters and returns region if it matches to the condition.
 // when they fail, it does not change the location.
@@ -45,6 +47,7 @@ inline std::string show_char(const char c)
         buf.fill('\0');
         const auto r = std::snprintf(
                 buf.data(), buf.size(), "0x%02x", static_cast<int>(c) & 0xFF);
+        (void) r; // Unused variable warning
         assert(r == static_cast<int>(buf.size()) - 1);
         return std::string(buf.data());
     }
@@ -55,13 +58,9 @@ struct character
 {
     static constexpr char target = C;
 
-    template<typename Cont>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc)
+    static result<region, none_t>
+    invoke(location& loc)
     {
-        static_assert(std::is_same<char, typename Cont::value_type>::value,
-                      "internal error: container::value_type should be `char`.");
-
         if(loc.iter() == loc.end()) {return none();}
         const auto first = loc.iter();
 
@@ -72,7 +71,7 @@ struct character
         }
         loc.advance(); // update location
 
-        return ok(region<Cont>(loc, first, loc.iter()));
+        return ok(region(loc, first, loc.iter()));
     }
 };
 template<char C>
@@ -88,13 +87,9 @@ struct in_range
     static constexpr char upper = Up;
     static constexpr char lower = Low;
 
-    template<typename Cont>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc)
+    static result<region, none_t>
+    invoke(location& loc)
     {
-        static_assert(std::is_same<char, typename Cont::value_type>::value,
-                      "internal error: container::value_type should be `char`.");
-
         if(loc.iter() == loc.end()) {return none();}
         const auto first = loc.iter();
 
@@ -105,7 +100,7 @@ struct in_range
         }
 
         loc.advance();
-        return ok(region<Cont>(loc, first, loc.iter()));
+        return ok(region(loc, first, loc.iter()));
     }
 };
 template<char L, char U> constexpr char in_range<L, U>::upper;
@@ -116,13 +111,9 @@ template<char L, char U> constexpr char in_range<L, U>::lower;
 template<typename Combinator>
 struct exclude
 {
-    template<typename Cont>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc)
+    static result<region, none_t>
+    invoke(location& loc)
     {
-        static_assert(std::is_same<char, typename Cont::value_type>::value,
-                      "internal error: container::value_type should be `char`.");
-
         if(loc.iter() == loc.end()) {return none();}
         auto first = loc.iter();
 
@@ -133,7 +124,7 @@ struct exclude
             return none();
         }
         loc.reset(std::next(first)); // XXX maybe loc.advance() is okay but...
-        return ok(region<Cont>(loc, first, loc.iter()));
+        return ok(region(loc, first, loc.iter()));
     }
 };
 
@@ -141,19 +132,15 @@ struct exclude
 template<typename Combinator>
 struct maybe
 {
-    template<typename Cont>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc)
+    static result<region, none_t>
+    invoke(location& loc)
     {
-        static_assert(std::is_same<char, typename Cont::value_type>::value,
-                      "internal error: container::value_type should be `char`.");
-
         const auto rslt = Combinator::invoke(loc);
         if(rslt.is_ok())
         {
             return rslt;
         }
-        return ok(region<Cont>(loc));
+        return ok(region(loc));
     }
 };
 
@@ -163,13 +150,9 @@ struct sequence;
 template<typename Head, typename ... Tail>
 struct sequence<Head, Tail...>
 {
-    template<typename Cont>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc)
+    static result<region, none_t>
+    invoke(location& loc)
     {
-        static_assert(std::is_same<char, typename Cont::value_type>::value,
-                      "internal error: container::value_type should be `char`.");
-
         const auto first = loc.iter();
         const auto rslt = Head::invoke(loc);
         if(rslt.is_err())
@@ -181,9 +164,9 @@ struct sequence<Head, Tail...>
     }
 
     // called from the above function only, recursively.
-    template<typename Cont, typename Iterator>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc, region<Cont> reg, Iterator first)
+    template<typename Iterator>
+    static result<region, none_t>
+    invoke(location& loc, region reg, Iterator first)
     {
         const auto rslt = Head::invoke(loc);
         if(rslt.is_err())
@@ -200,9 +183,9 @@ template<typename Head>
 struct sequence<Head>
 {
     // would be called from sequence<T ...>::invoke only.
-    template<typename Cont, typename Iterator>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc, region<Cont> reg, Iterator first)
+    template<typename Iterator>
+    static result<region, none_t>
+    invoke(location& loc, region reg, Iterator first)
     {
         const auto rslt = Head::invoke(loc);
         if(rslt.is_err())
@@ -221,13 +204,9 @@ struct either;
 template<typename Head, typename ... Tail>
 struct either<Head, Tail...>
 {
-    template<typename Cont>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc)
+    static result<region, none_t>
+    invoke(location& loc)
     {
-        static_assert(std::is_same<char, typename Cont::value_type>::value,
-                      "internal error: container::value_type should be `char`.");
-
         const auto rslt = Head::invoke(loc);
         if(rslt.is_ok()) {return rslt;}
         return either<Tail...>::invoke(loc);
@@ -236,12 +215,9 @@ struct either<Head, Tail...>
 template<typename Head>
 struct either<Head>
 {
-    template<typename Cont>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc)
+    static result<region, none_t>
+    invoke(location& loc)
     {
-        static_assert(std::is_same<char, typename Cont::value_type>::value,
-                      "internal error: container::value_type should be `char`.");
         return Head::invoke(loc);
     }
 };
@@ -256,11 +232,10 @@ struct unlimited{};
 template<typename T, std::size_t N>
 struct repeat<T, exactly<N>>
 {
-    template<typename Cont>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc)
+    static result<region, none_t>
+    invoke(location& loc)
     {
-        region<Cont> retval(loc);
+        region retval(loc);
         const auto first = loc.iter();
         for(std::size_t i=0; i<N; ++i)
         {
@@ -279,11 +254,10 @@ struct repeat<T, exactly<N>>
 template<typename T, std::size_t N>
 struct repeat<T, at_least<N>>
 {
-    template<typename Cont>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc)
+    static result<region, none_t>
+    invoke(location& loc)
     {
-        region<Cont> retval(loc);
+        region retval(loc);
 
         const auto first = loc.iter();
         for(std::size_t i=0; i<N; ++i)
@@ -311,11 +285,10 @@ struct repeat<T, at_least<N>>
 template<typename T>
 struct repeat<T, unlimited>
 {
-    template<typename Cont>
-    static result<region<Cont>, none_t>
-    invoke(location<Cont>& loc)
+    static result<region, none_t>
+    invoke(location& loc)
     {
-        region<Cont> retval(loc);
+        region retval(loc);
         while(true)
         {
             auto rslt = T::invoke(loc);

toml/comments.hpp

@@ -0,0 +1,466 @@
+//     Copyright Toru Niina 2019.
+// Distributed under the MIT License.
+#ifndef TOML11_COMMENTS_HPP
+#define TOML11_COMMENTS_HPP
+#include <initializer_list>
+#include <iterator>
+#include <stdexcept>
+#include <string>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+// This file provides mainly two classes, `preserve_comments` and `discard_comments`.
+// Those two are a container that have the same interface as `std::vector<std::string>`
+// but bahaves in the opposite way. `preserve_comments` is just the same as
+// `std::vector<std::string>` and each `std::string` corresponds to a comment line.
+// Conversely, `discard_comments` discards all the strings and ignores everything
+// assigned in it. `discard_comments` is always empty and you will encounter an
+// error whenever you access to the element.
+namespace toml
+{
+struct discard_comments; // forward decl
+
+// use it in the following way
+//
+// const toml::basic_value<toml::preserve_comments> data =
+//     toml::parse<toml::preserve_comments>("example.toml");
+//
+// the interface is almost the same as std::vector<std::string>.
+struct preserve_comments
+{
+    // `container_type` is not provided in discard_comments.
+    // do not use this inner-type in a generic code.
+    using container_type         = std::vector<std::string>;
+
+    using size_type              = container_type::size_type;
+    using difference_type        = container_type::difference_type;
+    using value_type             = container_type::value_type;
+    using reference              = container_type::reference;
+    using const_reference        = container_type::const_reference;
+    using pointer                = container_type::pointer;
+    using const_pointer          = container_type::const_pointer;
+    using iterator               = container_type::iterator;
+    using const_iterator         = container_type::const_iterator;
+    using reverse_iterator       = container_type::reverse_iterator;
+    using const_reverse_iterator = container_type::const_reverse_iterator;
+
+    preserve_comments()  = default;
+    ~preserve_comments() = default;
+    preserve_comments(preserve_comments const&) = default;
+    preserve_comments(preserve_comments &&)     = default;
+    preserve_comments& operator=(preserve_comments const&) = default;
+    preserve_comments& operator=(preserve_comments &&)     = default;
+
+    explicit preserve_comments(const std::vector<std::string>& c): comments(c){}
+    explicit preserve_comments(std::vector<std::string>&& c)
+        : comments(std::move(c))
+    {}
+    preserve_comments& operator=(const std::vector<std::string>& c)
+    {
+        comments = c;
+        return *this;
+    }
+    preserve_comments& operator=(std::vector<std::string>&& c)
+    {
+        comments = std::move(c);
+        return *this;
+    }
+
+    explicit preserve_comments(const discard_comments&) {}
+
+    explicit preserve_comments(size_type n): comments(n) {}
+    preserve_comments(size_type n, const std::string& x): comments(n, x) {}
+    preserve_comments(std::initializer_list<std::string> x): comments(x) {}
+    template<typename InputIterator>
+    preserve_comments(InputIterator first, InputIterator last)
+        : comments(first, last)
+    {}
+
+    template<typename InputIterator>
+    void assign(InputIterator first, InputIterator last) {comments.assign(first, last);}
+    void assign(std::initializer_list<std::string> ini)  {comments.assign(ini);}
+    void assign(size_type n, const std::string& val)     {comments.assign(n, val);}
+
+    // Related to the issue #97.
+    //
+    // It is known that `std::vector::insert` and `std::vector::erase` in
+    // the standard library implementation included in GCC 4.8.5 takes
+    // `std::vector::iterator` instead of `std::vector::const_iterator`.
+    // Because of the const-correctness, we cannot convert a `const_iterator` to
+    // an `iterator`. It causes compilation error in GCC 4.8.5.
+#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__) && !defined(__clang__)
+#  if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) <= 40805
+#    define TOML11_WORKAROUND_GCC_4_8_X_STANDARD_LIBRARY_IMPLEMENTATION
+#  endif
+#endif
+
+#ifdef TOML11_WORKAROUND_GCC_4_8_X_STANDARD_LIBRARY_IMPLEMENTATION
+    iterator insert(iterator p, const std::string& x)
+    {
+        return comments.insert(p, x);
+    }
+    iterator insert(iterator p, std::string&&      x)
+    {
+        return comments.insert(p, std::move(x));
+    }
+    void insert(iterator p, size_type n, const std::string& x)
+    {
+        return comments.insert(p, n, x);
+    }
+    template<typename InputIterator>
+    void insert(iterator p, InputIterator first, InputIterator last)
+    {
+        return comments.insert(p, first, last);
+    }
+    void insert(iterator p, std::initializer_list<std::string> ini)
+    {
+        return comments.insert(p, ini);
+    }
+
+    template<typename ... Ts>
+    iterator emplace(iterator p, Ts&& ... args)
+    {
+        return comments.emplace(p, std::forward<Ts>(args)...);
+    }
+
+    iterator erase(iterator pos) {return comments.erase(pos);}
+    iterator erase(iterator first, iterator last)
+    {
+        return comments.erase(first, last);
+    }
+#else
+    iterator insert(const_iterator p, const std::string& x)
+    {
+        return comments.insert(p, x);
+    }
+    iterator insert(const_iterator p, std::string&&      x)
+    {
+        return comments.insert(p, std::move(x));
+    }
+    iterator insert(const_iterator p, size_type n, const std::string& x)
+    {
+        return comments.insert(p, n, x);
+    }
+    template<typename InputIterator>
+    iterator insert(const_iterator p, InputIterator first, InputIterator last)
+    {
+        return comments.insert(p, first, last);
+    }
+    iterator insert(const_iterator p, std::initializer_list<std::string> ini)
+    {
+        return comments.insert(p, ini);
+    }
+
+    template<typename ... Ts>
+    iterator emplace(const_iterator p, Ts&& ... args)
+    {
+        return comments.emplace(p, std::forward<Ts>(args)...);
+    }
+
+    iterator erase(const_iterator pos) {return comments.erase(pos);}
+    iterator erase(const_iterator first, const_iterator last)
+    {
+        return comments.erase(first, last);
+    }
+#endif
+
+    void swap(preserve_comments& other) {comments.swap(other.comments);}
+
+    void push_back(const std::string& v) {comments.push_back(v);}
+    void push_back(std::string&&      v) {comments.push_back(std::move(v));}
+    void pop_back()                      {comments.pop_back();}
+
+    template<typename ... Ts>
+    void emplace_back(Ts&& ... args) {comments.emplace_back(std::forward<Ts>(args)...);}
+
+    void clear() {comments.clear();}
+
+    size_type size()     const noexcept {return comments.size();}
+    size_type max_size() const noexcept {return comments.max_size();}
+    size_type capacity() const noexcept {return comments.capacity();}
+    bool      empty()    const noexcept {return comments.empty();}
+
+    void reserve(size_type n)                      {comments.reserve(n);}
+    void resize(size_type n)                       {comments.resize(n);}
+    void resize(size_type n, const std::string& c) {comments.resize(n, c);}
+    void shrink_to_fit()                           {comments.shrink_to_fit();}
+
+    reference       operator[](const size_type n)       noexcept {return comments[n];}
+    const_reference operator[](const size_type n) const noexcept {return comments[n];}
+    reference       at(const size_type n)       {return comments.at(n);}
+    const_reference at(const size_type n) const {return comments.at(n);}
+    reference       front()       noexcept {return comments.front();}
+    const_reference front() const noexcept {return comments.front();}
+    reference       back()        noexcept {return comments.back();}
+    const_reference back()  const noexcept {return comments.back();}
+
+    pointer         data()        noexcept {return comments.data();}
+    const_pointer   data()  const noexcept {return comments.data();}
+
+    iterator       begin()        noexcept {return comments.begin();}
+    iterator       end()          noexcept {return comments.end();}
+    const_iterator begin()  const noexcept {return comments.begin();}
+    const_iterator end()    const noexcept {return comments.end();}
+    const_iterator cbegin() const noexcept {return comments.cbegin();}
+    const_iterator cend()   const noexcept {return comments.cend();}
+
+    reverse_iterator       rbegin()        noexcept {return comments.rbegin();}
+    reverse_iterator       rend()          noexcept {return comments.rend();}
+    const_reverse_iterator rbegin()  const noexcept {return comments.rbegin();}
+    const_reverse_iterator rend()    const noexcept {return comments.rend();}
+    const_reverse_iterator crbegin() const noexcept {return comments.crbegin();}
+    const_reverse_iterator crend()   const noexcept {return comments.crend();}
+
+    friend bool operator==(const preserve_comments&, const preserve_comments&);
+    friend bool operator!=(const preserve_comments&, const preserve_comments&);
+    friend bool operator< (const preserve_comments&, const preserve_comments&);
+    friend bool operator<=(const preserve_comments&, const preserve_comments&);
+    friend bool operator> (const preserve_comments&, const preserve_comments&);
+    friend bool operator>=(const preserve_comments&, const preserve_comments&);
+
+    friend void swap(preserve_comments&, std::vector<std::string>&);
+    friend void swap(std::vector<std::string>&, preserve_comments&);
+
+  private:
+
+    container_type comments;
+};
+
+inline bool operator==(const preserve_comments& lhs, const preserve_comments& rhs) {return lhs.comments == rhs.comments;}
+inline bool operator!=(const preserve_comments& lhs, const preserve_comments& rhs) {return lhs.comments != rhs.comments;}
+inline bool operator< (const preserve_comments& lhs, const preserve_comments& rhs) {return lhs.comments <  rhs.comments;}
+inline bool operator<=(const preserve_comments& lhs, const preserve_comments& rhs) {return lhs.comments <= rhs.comments;}
+inline bool operator> (const preserve_comments& lhs, const preserve_comments& rhs) {return lhs.comments >  rhs.comments;}
+inline bool operator>=(const preserve_comments& lhs, const preserve_comments& rhs) {return lhs.comments >= rhs.comments;}
+
+inline void swap(preserve_comments& lhs, preserve_comments& rhs)
+{
+    lhs.swap(rhs);
+    return;
+}
+inline void swap(preserve_comments& lhs, std::vector<std::string>& rhs)
+{
+    lhs.comments.swap(rhs);
+    return;
+}
+inline void swap(std::vector<std::string>& lhs, preserve_comments& rhs)
+{
+    lhs.swap(rhs.comments);
+    return;
+}
+
+template<typename charT, typename traits>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os, const preserve_comments& com)
+{
+    for(const auto& c : com)
+    {
+        os << '#' << c << '\n';
+    }
+    return os;
+}
+
+namespace detail
+{
+
+// To provide the same interface with `preserve_comments`, `discard_comments`
+// should have an iterator. But it does not contain anything, so we need to
+// add an iterator that points nothing.
+//
+// It always points null, so DO NOT unwrap this iterator. It always crashes
+// your program.
+template<typename T, bool is_const>
+struct empty_iterator
+{
+    using value_type        = T;
+    using reference_type    = typename std::conditional<is_const, T const&, T&>::type;
+    using pointer_type      = typename std::conditional<is_const, T const*, T*>::type;
+    using difference_type   = std::ptrdiff_t;
+    using iterator_category = std::random_access_iterator_tag;
+
+    empty_iterator()  = default;
+    ~empty_iterator() = default;
+    empty_iterator(empty_iterator const&) = default;
+    empty_iterator(empty_iterator &&)     = default;
+    empty_iterator& operator=(empty_iterator const&) = default;
+    empty_iterator& operator=(empty_iterator &&)     = default;
+
+    // DO NOT call these operators.
+    reference_type operator*()  const noexcept {std::terminate();}
+    pointer_type   operator->() const noexcept {return nullptr;}
+    reference_type operator[](difference_type) const noexcept {return this->operator*();}
+
+    // These operators do nothing.
+    empty_iterator& operator++()    noexcept {return *this;}
+    empty_iterator  operator++(int) noexcept {return *this;}
+    empty_iterator& operator--()    noexcept {return *this;}
+    empty_iterator  operator--(int) noexcept {return *this;}
+
+    empty_iterator& operator+=(difference_type) noexcept {return *this;}
+    empty_iterator& operator-=(difference_type) noexcept {return *this;}
+
+    empty_iterator  operator+(difference_type) const noexcept {return *this;}
+    empty_iterator  operator-(difference_type) const noexcept {return *this;}
+};
+
+template<typename T, bool C>
+bool operator==(const empty_iterator<T, C>&, const empty_iterator<T, C>&) noexcept {return true;}
+template<typename T, bool C>
+bool operator!=(const empty_iterator<T, C>&, const empty_iterator<T, C>&) noexcept {return false;}
+template<typename T, bool C>
+bool operator< (const empty_iterator<T, C>&, const empty_iterator<T, C>&) noexcept {return false;}
+template<typename T, bool C>
+bool operator<=(const empty_iterator<T, C>&, const empty_iterator<T, C>&) noexcept {return true;}
+template<typename T, bool C>
+bool operator> (const empty_iterator<T, C>&, const empty_iterator<T, C>&) noexcept {return false;}
+template<typename T, bool C>
+bool operator>=(const empty_iterator<T, C>&, const empty_iterator<T, C>&) noexcept {return true;}
+
+template<typename T, bool C>
+typename empty_iterator<T, C>::difference_type
+operator-(const empty_iterator<T, C>&, const empty_iterator<T, C>&) noexcept {return 0;}
+
+template<typename T, bool C>
+empty_iterator<T, C>
+operator+(typename empty_iterator<T, C>::difference_type, const empty_iterator<T, C>& rhs) noexcept {return rhs;}
+template<typename T, bool C>
+empty_iterator<T, C>
+operator+(const empty_iterator<T, C>& lhs, typename empty_iterator<T, C>::difference_type) noexcept {return lhs;}
+
+} // detail
+
+// The default comment type. It discards all the comments. It requires only one
+// byte to contain, so the memory footprint is smaller than preserve_comments.
+//
+// It just ignores `push_back`, `insert`, `erase`, and any other modifications.
+// IT always returns size() == 0, the iterator taken by `begin()` is always the
+// same as that of `end()`, and accessing through `operator[]` or iterators
+// always causes a segmentation fault. DO NOT access to the element of this.
+//
+// Why this is chose as the default type is because the last version (2.x.y)
+// does not contain any comments in a value. To minimize the impact on the
+// efficiency, this is choosed as a default.
+//
+// To reduce the memory footprint, later we can try empty base optimization (EBO).
+struct discard_comments
+{
+    using size_type              = std::size_t;
+    using difference_type        = std::ptrdiff_t;
+    using value_type             = std::string;
+    using reference              = std::string&;
+    using const_reference        = std::string const&;
+    using pointer                = std::string*;
+    using const_pointer          = std::string const*;
+    using iterator               = detail::empty_iterator<std::string, false>;
+    using const_iterator         = detail::empty_iterator<std::string, true>;
+    using reverse_iterator       = detail::empty_iterator<std::string, false>;
+    using const_reverse_iterator = detail::empty_iterator<std::string, true>;
+
+    discard_comments() = default;
+    ~discard_comments() = default;
+    discard_comments(discard_comments const&) = default;
+    discard_comments(discard_comments &&)     = default;
+    discard_comments& operator=(discard_comments const&) = default;
+    discard_comments& operator=(discard_comments &&)     = default;
+
+    explicit discard_comments(const std::vector<std::string>&) noexcept {}
+    explicit discard_comments(std::vector<std::string>&&)      noexcept {}
+    discard_comments& operator=(const std::vector<std::string>&) noexcept {return *this;}
+    discard_comments& operator=(std::vector<std::string>&&)      noexcept {return *this;}
+
+    explicit discard_comments(const preserve_comments&)        noexcept {}
+
+    explicit discard_comments(size_type) noexcept {}
+    discard_comments(size_type, const std::string&) noexcept {}
+    discard_comments(std::initializer_list<std::string>) noexcept {}
+    template<typename InputIterator>
+    discard_comments(InputIterator, InputIterator) noexcept {}
+
+    template<typename InputIterator>
+    void assign(InputIterator, InputIterator)       noexcept {}
+    void assign(std::initializer_list<std::string>) noexcept {}
+    void assign(size_type, const std::string&)      noexcept {}
+
+    iterator insert(const_iterator, const std::string&)                 {return iterator{};}
+    iterator insert(const_iterator, std::string&&)                      {return iterator{};}
+    iterator insert(const_iterator, size_type, const std::string&)      {return iterator{};}
+    template<typename InputIterator>
+    iterator insert(const_iterator, InputIterator, InputIterator)       {return iterator{};}
+    iterator insert(const_iterator, std::initializer_list<std::string>) {return iterator{};}
+
+    template<typename ... Ts>
+    iterator emplace(const_iterator, Ts&& ...)     {return iterator{};}
+    iterator erase(const_iterator)                 {return iterator{};}
+    iterator erase(const_iterator, const_iterator) {return iterator{};}
+
+    void swap(discard_comments&) {return;}
+
+    void push_back(const std::string&) {return;}
+    void push_back(std::string&&     ) {return;}
+    void pop_back()                    {return;}
+
+    template<typename ... Ts>
+    void emplace_back(Ts&& ...) {return;}
+
+    void clear() {return;}
+
+    size_type size()     const noexcept {return 0;}
+    size_type max_size() const noexcept {return 0;}
+    size_type capacity() const noexcept {return 0;}
+    bool      empty()    const noexcept {return true;}
+
+    void reserve(size_type)                    {return;}
+    void resize(size_type)                     {return;}
+    void resize(size_type, const std::string&) {return;}
+    void shrink_to_fit()                       {return;}
+
+    // DO NOT access to the element of this container. This container is always
+    // empty, so accessing through operator[], front/back, data causes address
+    // error.
+
+    reference       operator[](const size_type)       noexcept {return *data();}
+    const_reference operator[](const size_type) const noexcept {return *data();}
+    reference       at(const size_type)       {throw std::out_of_range("toml::discard_comment is always empty.");}
+    const_reference at(const size_type) const {throw std::out_of_range("toml::discard_comment is always empty.");}
+    reference       front()       noexcept {return *data();}
+    const_reference front() const noexcept {return *data();}
+    reference       back()        noexcept {return *data();}
+    const_reference back()  const noexcept {return *data();}
+
+    pointer         data()        noexcept {return nullptr;}
+    const_pointer   data()  const noexcept {return nullptr;}
+
+    iterator       begin()        noexcept {return iterator{};}
+    iterator       end()          noexcept {return iterator{};}
+    const_iterator begin()  const noexcept {return const_iterator{};}
+    const_iterator end()    const noexcept {return const_iterator{};}
+    const_iterator cbegin() const noexcept {return const_iterator{};}
+    const_iterator cend()   const noexcept {return const_iterator{};}
+
+    reverse_iterator       rbegin()        noexcept {return iterator{};}
+    reverse_iterator       rend()          noexcept {return iterator{};}
+    const_reverse_iterator rbegin()  const noexcept {return const_iterator{};}
+    const_reverse_iterator rend()    const noexcept {return const_iterator{};}
+    const_reverse_iterator crbegin() const noexcept {return const_iterator{};}
+    const_reverse_iterator crend()   const noexcept {return const_iterator{};}
+};
+
+inline bool operator==(const discard_comments&, const discard_comments&) noexcept {return true;}
+inline bool operator!=(const discard_comments&, const discard_comments&) noexcept {return false;}
+inline bool operator< (const discard_comments&, const discard_comments&) noexcept {return false;}
+inline bool operator<=(const discard_comments&, const discard_comments&) noexcept {return true;}
+inline bool operator> (const discard_comments&, const discard_comments&) noexcept {return false;}
+inline bool operator>=(const discard_comments&, const discard_comments&) noexcept {return true;}
+
+inline void swap(const discard_comments&, const discard_comments&) noexcept {return;}
+
+template<typename charT, typename traits>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os, const discard_comments&)
+{
+    return os;
+}
+
+} // toml11
+#endif// TOML11_COMMENTS_HPP

toml/datetime.hpp

@@ -2,15 +2,16 @@
 // Distributed under the MIT License.
 #ifndef TOML11_DATETIME_HPP
 #define TOML11_DATETIME_HPP
-#include <chrono>
-#include <tuple>
-#include <array>
-#include <ostream>
-#include <iomanip>
 #include <cstdint>
 #include <cstdlib>
 #include <ctime>
 
+#include <array>
+#include <chrono>
+#include <iomanip>
+#include <ostream>
+#include <tuple>
+
 namespace toml
 {
 
@@ -20,7 +21,7 @@ namespace toml
 namespace detail
 {
 // TODO: find more sophisticated way to handle this
-#if _POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _BSD_SOURCE || _SVID_SOURCE || _POSIX_SOURCE
+#if (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 1) || defined(_XOPEN_SOURCE) || defined(_BSD_SOURCE) || defined(_SVID_SOURCE) || defined(_POSIX_SOURCE)
 inline std::tm localtime_s(const std::time_t* src)
 {
     std::tm dst;
@@ -28,7 +29,14 @@ inline std::tm localtime_s(const std::time_t* src)
     if (!result) { throw std::runtime_error("localtime_r failed."); }
     return dst;
 }
-#elif _MSC_VER
+inline std::tm gmtime_s(const std::time_t* src)
+{
+    std::tm dst;
+    const auto result = ::gmtime_r(src, &dst);
+    if (!result) { throw std::runtime_error("gmtime_r failed."); }
+    return dst;
+}
+#elif defined(_MSC_VER)
 inline std::tm localtime_s(const std::time_t* src)
 {
     std::tm dst;
@@ -36,17 +44,30 @@ inline std::tm localtime_s(const std::time_t* src)
     if (result) { throw std::runtime_error("localtime_s failed."); }
     return dst;
 }
-#else
+inline std::tm gmtime_s(const std::time_t* src)
+{
+    std::tm dst;
+    const auto result = ::gmtime_s(&dst, src);
+    if (result) { throw std::runtime_error("gmtime_s failed."); }
+    return dst;
+}
+#else // fallback. not threadsafe
 inline std::tm localtime_s(const std::time_t* src)
 {
     const auto result = std::localtime(src);
     if (!result) { throw std::runtime_error("localtime failed."); }
     return *result;
 }
+inline std::tm gmtime_s(const std::time_t* src)
+{
+    const auto result = std::gmtime(src);
+    if (!result) { throw std::runtime_error("gmtime failed."); }
+    return *result;
+}
 #endif
 } // detail
 
-enum class month_t : std::int8_t
+enum class month_t : std::uint8_t
 {
     Jan =  0,
     Feb =  1,
@@ -98,9 +119,9 @@ struct local_date
         t.tm_sec   = 0;
         t.tm_min   = 0;
         t.tm_hour  = 0;
-        t.tm_mday  = this->day;
-        t.tm_mon   = this->month;
-        t.tm_year  = this->year - 1900;
+        t.tm_mday  = static_cast<int>(this->day);
+        t.tm_mon   = static_cast<int>(this->month);
+        t.tm_year  = static_cast<int>(this->year) - 1900;
         t.tm_wday  = 0; // the value will be ignored
         t.tm_yday  = 0; // the value will be ignored
         t.tm_isdst = -1;
@@ -152,9 +173,9 @@ template<typename charT, typename traits>
 std::basic_ostream<charT, traits>&
 operator<<(std::basic_ostream<charT, traits>& os, const local_date& date)
 {
-    os << std::setfill('0') << std::setw(4) << static_cast<int>(date.year     ) << '-';
-    os << std::setfill('0') << std::setw(2) << static_cast<int>(date.month + 1) << '-';
-    os << std::setfill('0') << std::setw(2) << static_cast<int>(date.day      );
+    os << std::setfill('0') << std::setw(4) << static_cast<int>(date.year )     << '-';
+    os << std::setfill('0') << std::setw(2) << static_cast<int>(date.month) + 1 << '-';
+    os << std::setfill('0') << std::setw(2) << static_cast<int>(date.day  )    ;
     return os;
 }
 
@@ -188,22 +209,22 @@ struct local_time
     explicit local_time(const std::chrono::duration<Rep, Period>& t)
     {
         const auto h = std::chrono::duration_cast<std::chrono::hours>(t);
-        this->hour = h.count();
+        this->hour = static_cast<std::uint8_t>(h.count());
         const auto t2 = t - h;
         const auto m = std::chrono::duration_cast<std::chrono::minutes>(t2);
-        this->minute = m.count();
+        this->minute = static_cast<std::uint8_t>(m.count());
         const auto t3 = t2 - m;
         const auto s = std::chrono::duration_cast<std::chrono::seconds>(t3);
-        this->second = s.count();
+        this->second = static_cast<std::uint8_t>(s.count());
         const auto t4 = t3 - s;
         const auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(t4);
-        this->millisecond = ms.count();
+        this->millisecond = static_cast<std::uint16_t>(ms.count());
         const auto t5 = t4 - ms;
         const auto us = std::chrono::duration_cast<std::chrono::microseconds>(t5);
-        this->microsecond = us.count();
+        this->microsecond = static_cast<std::uint16_t>(us.count());
         const auto t6 = t5 - us;
         const auto ns = std::chrono::duration_cast<std::chrono::nanoseconds>(t6);
-        this->nanosecond = ns.count();
+        this->nanosecond = static_cast<std::uint16_t>(ns.count());
     }
 
     operator std::chrono::nanoseconds() const
@@ -378,10 +399,31 @@ struct local_datetime
     {
         using internal_duration =
             typename std::chrono::system_clock::time_point::duration;
+
+        // Normally DST begins at A.M. 3 or 4. If we re-use conversion operator
+        // of local_date and local_time independently, the conversion fails if
+        // it is the day when DST begins or ends. Since local_date considers the
+        // time is 00:00 A.M. and local_time does not consider DST because it
+        // does not have any date information. We need to consider both date and
+        // time information at the same time to convert it correctly.
+
+        std::tm t;
+        t.tm_sec   = static_cast<int>(this->time.second);
+        t.tm_min   = static_cast<int>(this->time.minute);
+        t.tm_hour  = static_cast<int>(this->time.hour);
+        t.tm_mday  = static_cast<int>(this->date.day);
+        t.tm_mon   = static_cast<int>(this->date.month);
+        t.tm_year  = static_cast<int>(this->date.year) - 1900;
+        t.tm_wday  = 0; // the value will be ignored
+        t.tm_yday  = 0; // the value will be ignored
+        t.tm_isdst = -1;
+
         // std::mktime returns date as local time zone. no conversion needed
-        auto dt = std::chrono::system_clock::time_point(this->date);
+        auto dt = std::chrono::system_clock::from_time_t(std::mktime(&t));
         dt += std::chrono::duration_cast<internal_duration>(
-                   std::chrono::nanoseconds(this->time));
+                std::chrono::milliseconds(this->time.millisecond) +
+                std::chrono::microseconds(this->time.microsecond) +
+                std::chrono::nanoseconds (this->time.nanosecond));
         return dt;
     }
 
@@ -447,40 +489,71 @@ struct offset_datetime
         : date(dt.date), time(dt.time), offset(o)
     {}
     explicit offset_datetime(const local_datetime& ld)
-        : date(ld.date), time(ld.time), offset(get_local_offset())
+        : date(ld.date), time(ld.time), offset(get_local_offset(nullptr))
+          // use the current local timezone offset
     {}
     explicit offset_datetime(const std::chrono::system_clock::time_point& tp)
-        : offset_datetime(local_datetime(tp))
-    {}
+        : offset(0, 0) // use gmtime
+    {
+        const auto timet = std::chrono::system_clock::to_time_t(tp);
+        const auto tm    = detail::gmtime_s(&timet);
+        this->date = local_date(tm);
+        this->time = local_time(tm);
+    }
     explicit offset_datetime(const std::time_t& t)
-        : offset_datetime(local_datetime(t))
-    {}
+        : offset(0, 0) // use gmtime
+    {
+        const auto tm    = detail::gmtime_s(&t);
+        this->date = local_date(tm);
+        this->time = local_time(tm);
+    }
     explicit offset_datetime(const std::tm& t)
-        : offset_datetime(local_datetime(t))
-    {}
+        : offset(0, 0) // assume gmtime
+    {
+        this->date = local_date(t);
+        this->time = local_time(t);
+    }
 
     operator std::chrono::system_clock::time_point() const
     {
         // get date-time
         using internal_duration =
             typename std::chrono::system_clock::time_point::duration;
-        std::chrono::system_clock::time_point tp =
-            std::chrono::system_clock::time_point(this->date) +
-            std::chrono::duration_cast<internal_duration>(
-                   std::chrono::nanoseconds(this->time));
 
-        // get date-time in UTC. let's say we are in +09:00 (JPN).
-        // writing 12:00:00 in +09:00 means 03:00:00Z. to represent
-        // 12:00:00Z, first we need to add +09:00.
-        const auto ofs = get_local_offset();
+        // first, convert it to local date-time information in the same way as
+        // local_datetime does. later we will use time_t to adjust time offset.
+        std::tm t;
+        t.tm_sec   = static_cast<int>(this->time.second);
+        t.tm_min   = static_cast<int>(this->time.minute);
+        t.tm_hour  = static_cast<int>(this->time.hour);
+        t.tm_mday  = static_cast<int>(this->date.day);
+        t.tm_mon   = static_cast<int>(this->date.month);
+        t.tm_year  = static_cast<int>(this->date.year) - 1900;
+        t.tm_wday  = 0; // the value will be ignored
+        t.tm_yday  = 0; // the value will be ignored
+        t.tm_isdst = -1;
+        const std::time_t tp_loc = std::mktime(std::addressof(t));
+
+        auto tp = std::chrono::system_clock::from_time_t(tp_loc);
+        tp += std::chrono::duration_cast<internal_duration>(
+                std::chrono::milliseconds(this->time.millisecond) +
+                std::chrono::microseconds(this->time.microsecond) +
+                std::chrono::nanoseconds (this->time.nanosecond));
+
+        // Since mktime uses local time zone, it should be corrected.
+        // `12:00:00+09:00` means `03:00:00Z`. So mktime returns `03:00:00Z` if
+        // we are in `+09:00` timezone. To represent `12:00:00Z` there, we need
+        // to add `+09:00` to `03:00:00Z`.
+        //    Here, it uses the time_t converted from date-time info to handle
+        // daylight saving time.
+        const auto ofs = get_local_offset(std::addressof(tp_loc));
         tp += std::chrono::hours  (ofs.hour);
         tp += std::chrono::minutes(ofs.minute);
 
-        // here, tp represents 12:00:00 in UTC but we have offset information.
-        // we need to subtract it. For example, let's say the input is
-        // 12:00:00-08:00. now we have tp = 12:00:00Z as a result of the above
-        // conversion. But the actual time we need to return is 20:00:00Z
-        // because of -08:00.
+        // We got `12:00:00Z` by correcting local timezone applied by mktime.
+        // Then we will apply the offset. Let's say `12:00:00-08:00` is given.
+        // And now, we have `12:00:00Z`. `12:00:00-08:00` means `20:00:00Z`.
+        // So we need to subtract the offset.
         tp -= std::chrono::minutes(this->offset);
         return tp;
     }
@@ -500,11 +573,10 @@ struct offset_datetime
 
   private:
 
-    static time_offset get_local_offset()
+    static time_offset get_local_offset(const std::time_t* tp)
     {
-         // get current timezone
-        const auto tmp1 = std::time(nullptr);
-        const auto t    = detail::localtime_s(&tmp1);
+        // get local timezone with the same date-time information as mktime
+        const auto t = detail::localtime_s(tp);
 
         std::array<char, 6> buf;
         const auto result = std::strftime(buf.data(), 6, "%z", &t); // +hhmm\0

toml/exception.hpp

@@ -5,21 +5,29 @@
 #include <stdexcept>
 #include <string>
 
+#include "source_location.hpp"
+
 namespace toml
 {
 
 struct exception : public std::exception
 {
   public:
+    explicit exception(const source_location& loc): loc_(loc) {}
     virtual ~exception() noexcept override = default;
     virtual const char* what() const noexcept override {return "";}
+    virtual source_location const& location() const noexcept {return loc_;}
+
+  protected:
+    source_location loc_;
 };
 
 struct syntax_error : public toml::exception
 {
   public:
-    explicit syntax_error(const std::string& what_arg) : what_(what_arg){}
-    explicit syntax_error(const char* what_arg)        : what_(what_arg){}
+    explicit syntax_error(const std::string& what_arg, const source_location& loc)
+        : exception(loc), what_(what_arg)
+    {}
     virtual ~syntax_error() noexcept override = default;
     virtual const char* what() const noexcept override {return what_.c_str();}
 
@@ -30,8 +38,9 @@ struct syntax_error : public toml::exception
 struct type_error : public toml::exception
 {
   public:
-    explicit type_error(const std::string& what_arg) : what_(what_arg){}
-    explicit type_error(const char* what_arg)        : what_(what_arg){}
+    explicit type_error(const std::string& what_arg, const source_location& loc)
+        : exception(loc), what_(what_arg)
+    {}
     virtual ~type_error() noexcept override = default;
     virtual const char* what() const noexcept override {return what_.c_str();}
 
@@ -42,10 +51,12 @@ struct type_error : public toml::exception
 struct internal_error : public toml::exception
 {
   public:
-    explicit internal_error(const std::string& what_arg) : what_(what_arg){}
-    explicit internal_error(const char* what_arg)        : what_(what_arg){}
+    explicit internal_error(const std::string& what_arg, const source_location& loc)
+        : exception(loc), what_(what_arg)
+    {}
     virtual ~internal_error() noexcept override = default;
     virtual const char* what() const noexcept override {return what_.c_str();}
+
   protected:
     std::string what_;
 };

toml/from_toml.hpp

@@ -1,71 +0,0 @@
-//     Copyright Toru Niina 2017.
-// Distributed under the MIT License.
-#ifndef TOML11_FROM_TOML_HPP
-#define TOML11_FROM_TOML_HPP
-#include "get.hpp"
-
-namespace toml
-{
-
-template<typename T>
-void from_toml(T& x, const toml::value& v)
-{
-    x = toml::get<typename std::remove_reference<T>::type>(v);
-    return;
-}
-
-namespace detail
-{
-
-template<typename T>
-constexpr toml::value_t determine_castable_type()
-{
-    return check_type<T>() != toml::value_t::Unknown ? check_type<T>() :
-           toml::detail::is_map<T>::value            ? toml::value_t::Table :
-           toml::detail::is_container<T>::value      ? toml::value_t::Array :
-           toml::value_t::Unknown;
-}
-
-template<std::size_t N, typename ... Ts>
-struct from_toml_tie_impl
-{
-    constexpr static std::size_t   index = sizeof...(Ts) - N;
-    constexpr static toml::value_t type_index =
-        determine_castable_type<
-            typename std::tuple_element<index, std::tuple<Ts...>>::type>();
-
-    static void invoke(std::tuple<Ts& ...> tie, const toml::value& v)
-    {
-        // static_cast is needed because with intel c++ compiler, operator==
-        // is only defined when the two types are strictly equal, and type_index
-        // is const toml::value_t, while v.type() is toml::value_t.
-        if(static_cast<toml::value_t>(type_index) == v.type())
-        {
-            from_toml(std::get<index>(tie), v);
-            return;
-        }
-        return from_toml_tie_impl<N-1, Ts...>::invoke(tie, v);
-    }
-};
-
-template<typename ... Ts>
-struct from_toml_tie_impl<0, Ts...>
-{
-    static void invoke(std::tuple<Ts& ...>, const toml::value&)
-    {
-        return;
-    }
-};
-
-} // detail
-
-template<typename ... Ts>
-void from_toml(std::tuple<Ts& ...> tie, const toml::value& v)
-{
-    detail::from_toml_tie_impl<sizeof...(Ts), Ts...>::invoke(tie, v);
-    return;
-}
-
-
-} // toml
-#endif // TOML11_FROM_TOML

toml/lexer.hpp

@@ -2,12 +2,13 @@
 // Distributed under the MIT License.
 #ifndef TOML11_LEXER_HPP
 #define TOML11_LEXER_HPP
-#include "combinator.hpp"
-#include <stdexcept>
 #include <istream>
 #include <sstream>
+#include <stdexcept>
 #include <fstream>
 
+#include "combinator.hpp"
+
 namespace toml
 {
 namespace detail
@@ -63,12 +64,15 @@ using lex_integer = either<lex_bin_int, lex_oct_int, lex_hex_int, lex_dec_int>;
 using lex_inf = sequence<character<'i'>, character<'n'>, character<'f'>>;
 using lex_nan = sequence<character<'n'>, character<'a'>, character<'n'>>;
 using lex_special_float = sequence<maybe<lex_sign>, either<lex_inf, lex_nan>>;
-using lex_exponent_part = sequence<either<character<'e'>, character<'E'>>, lex_dec_int>;
 
 using lex_zero_prefixable_int = sequence<lex_digit, repeat<either<lex_digit,
-      sequence<lex_underscore, lex_digit>>, unlimited>>;
+    sequence<lex_underscore, lex_digit>>, unlimited>>;
+
 using lex_fractional_part = sequence<character<'.'>, lex_zero_prefixable_int>;
 
+using lex_exponent_part   = sequence<either<character<'e'>, character<'E'>>,
+        maybe<lex_sign>, lex_zero_prefixable_int>;
+
 using lex_float = either<lex_special_float,
       sequence<lex_dec_int, either<lex_exponent_part,
       sequence<lex_fractional_part, maybe<lex_exponent_part>>>>>;
@@ -115,9 +119,11 @@ using lex_local_time       = lex_partial_time;
 // ===========================================================================
 
 using lex_quotation_mark  = character<'"'>;
-using lex_basic_unescaped = exclude<either<in_range<0x00, 0x1F>,
+using lex_basic_unescaped = exclude<either<in_range<0x00, 0x08>, // 0x09 (tab)
+                                           in_range<0x0a, 0x1F>, // is allowed
                                            character<0x22>, character<0x5C>,
                                            character<0x7F>>>;
+
 using lex_escape          = character<'\\'>;
 using lex_escape_unicode_short = sequence<character<'u'>,
                                           repeat<lex_hex_dig, exactly<4>>>;
@@ -136,10 +142,46 @@ using lex_basic_string = sequence<lex_quotation_mark,
                                   repeat<lex_basic_char, unlimited>,
                                   lex_quotation_mark>;
 
+// After toml post-v0.5.0, it is explicitly clarified how quotes in ml-strings
+// are allowed to be used.
+// After this, the following strings are *explicitly* allowed.
+// - One or two `"`s in a multi-line basic string is allowed wherever it is.
+// - Three consecutive `"`s in a multi-line basic string is considered as a delimiter.
+// - One or two `"`s can appear just before or after the delimiter.
+// ```toml
+// str4 = """Here are two quotation marks: "". Simple enough."""
+// str5 = """Here are three quotation marks: ""\"."""
+// str6 = """Here are fifteen quotation marks: ""\"""\"""\"""\"""\"."""
+// str7 = """"This," she said, "is just a pointless statement.""""
+// ```
+// In the current implementation (v3.3.0), it is difficult to parse `str7` in
+// the above example. It is difficult to recognize `"` at the end of string body
+// collectly. It will be misunderstood as a `"""` delimiter and an additional,
+// invalid `"`. Like this:
+// ```console
+//   what():  [error] toml::parse_table: invalid line format
+//  --> hoge.toml
+//     |
+//  13 | str7 = """"This," she said, "is just a pointless statement.""""
+//     |                                                               ^- expected newline, but got '"'.
+// ```
+// As a quick workaround for this problem, `lex_ml_basic_string_delim` was
+// splitted into two, `lex_ml_basic_string_open` and `lex_ml_basic_string_close`.
+// `lex_ml_basic_string_open` allows only `"""`. `_close` allows 3-5 `"`s.
+// In parse_ml_basic_string() function, the trailing `"`s will be attached to
+// the string body.
+//
 using lex_ml_basic_string_delim = repeat<lex_quotation_mark, exactly<3>>;
-using lex_ml_basic_unescaped    = exclude<either<in_range<0x00, 0x1F>,
-                                                 character<0x5C>,
-                                                 character<0x7F>,
+using lex_ml_basic_string_open  = lex_ml_basic_string_delim;
+using lex_ml_basic_string_close = sequence<
+        repeat<lex_quotation_mark, exactly<3>>,
+        maybe<lex_quotation_mark>, maybe<lex_quotation_mark>
+    >;
+
+using lex_ml_basic_unescaped    = exclude<either<in_range<0x00, 0x08>, // 0x09
+                                                 in_range<0x0a, 0x1F>, // is tab
+                                                 character<0x5C>, // backslash
+                                                 character<0x7F>, // DEL
                                                  lex_ml_basic_string_delim>>;
 
 using lex_ml_basic_escaped_newline = sequence<
@@ -150,9 +192,9 @@ using lex_ml_basic_char = either<lex_ml_basic_unescaped, lex_escaped>;
 using lex_ml_basic_body = repeat<either<lex_ml_basic_char, lex_newline,
                                         lex_ml_basic_escaped_newline>,
                                  unlimited>;
-using lex_ml_basic_string = sequence<lex_ml_basic_string_delim,
+using lex_ml_basic_string = sequence<lex_ml_basic_string_open,
                                      lex_ml_basic_body,
-                                     lex_ml_basic_string_delim>;
+                                     lex_ml_basic_string_close>;
 
 using lex_literal_char = exclude<either<in_range<0x00, 0x08>,
                                         in_range<0x10, 0x19>, character<0x27>>>;
@@ -161,7 +203,13 @@ using lex_literal_string = sequence<lex_apostrophe,
                                     repeat<lex_literal_char, unlimited>,
                                     lex_apostrophe>;
 
+// the same reason as above.
 using lex_ml_literal_string_delim = repeat<lex_apostrophe, exactly<3>>;
+using lex_ml_literal_string_open  = lex_ml_literal_string_delim;
+using lex_ml_literal_string_close = sequence<
+        repeat<lex_apostrophe, exactly<3>>,
+        maybe<lex_apostrophe>, maybe<lex_apostrophe>
+    >;
 
 using lex_ml_literal_char = exclude<either<in_range<0x00, 0x08>,
                                            in_range<0x10, 0x1F>,
@@ -169,9 +217,9 @@ using lex_ml_literal_char = exclude<either<in_range<0x00, 0x08>,
                                            lex_ml_literal_string_delim>>;
 using lex_ml_literal_body = repeat<either<lex_ml_literal_char, lex_newline>,
                                    unlimited>;
-using lex_ml_literal_string = sequence<lex_ml_literal_string_delim,
+using lex_ml_literal_string = sequence<lex_ml_literal_string_open,
                                        lex_ml_literal_body,
-                                       lex_ml_literal_string_delim>;
+                                       lex_ml_literal_string_close>;
 
 using lex_string = either<lex_ml_basic_string,   lex_basic_string,
                           lex_ml_literal_string, lex_literal_string>;

toml/literal.hpp

@@ -11,12 +11,12 @@ inline namespace literals
 inline namespace toml_literals
 {
 
-inline ::toml::value operator"" _toml(const char* str, std::size_t len)
+// implementation
+inline ::toml::basic_value<::toml::discard_comments, std::unordered_map, std::vector>
+literal_internal_impl(::toml::detail::location loc)
 {
-    ::toml::detail::location<std::vector<char>>
-        loc(/* filename = */ std::string("TOML literal encoded in a C++ code"),
-            /* contents = */ std::vector<char>(str, str + len));
-
+    using value_type = ::toml::basic_value<
+        ::toml::discard_comments, std::unordered_map, std::vector>;
     // if there are some comments or empty lines, skip them.
     using skip_line = ::toml::detail::repeat<toml::detail::sequence<
             ::toml::detail::maybe<::toml::detail::lex_ws>,
@@ -53,7 +53,7 @@ inline ::toml::value operator"" _toml(const char* str, std::size_t len)
     // If it is neither a table-key or a array-of-table-key, it may be a value.
     if(!is_table_key && !is_aots_key)
     {
-        if(auto data = ::toml::detail::parse_value(loc))
+        if(auto data = ::toml::detail::parse_value<value_type>(loc))
         {
             return data.unwrap();
         }
@@ -70,21 +70,42 @@ inline ::toml::value operator"" _toml(const char* str, std::size_t len)
     // It is a valid toml file.
     // It should be parsed as if we parse a file with this content.
 
-    if(auto data = ::toml::detail::parse_toml_file(loc))
+    if(auto data = ::toml::detail::parse_toml_file<value_type>(loc))
     {
-        loc.reset(loc.begin()); // rollback to the top of the literal
-        // skip needless characters for error message
-        skip_line::invoke(loc); // skip the first several needless lines
-        skip_ws::invoke(loc);   // skip the first several needless whitespaces
-        return ::toml::value(std::move(data.unwrap()),
-                ::toml::detail::region<std::vector<char>>(std::move(loc)));
+        return data.unwrap();
     }
     else // none of them.
     {
-        throw ::toml::syntax_error(data.unwrap_err());
+        throw ::toml::syntax_error(data.unwrap_err(), source_location(loc));
     }
+
 }
 
+inline ::toml::basic_value<::toml::discard_comments, std::unordered_map, std::vector>
+operator"" _toml(const char* str, std::size_t len)
+{
+    ::toml::detail::location loc(
+            std::string("TOML literal encoded in a C++ code"),
+            std::vector<char>(str, str + len));
+    return literal_internal_impl(std::move(loc));
+}
+
+// value of __cplusplus in C++2a/20 mode is not fixed yet along compilers.
+// So here we use the feature test macro for `char8_t` itself.
+#if defined(__cpp_char8_t) && __cpp_char8_t >= 201811L
+// value of u8"" literal has been changed from char to char8_t and char8_t is
+// NOT compatible to char
+inline ::toml::basic_value<::toml::discard_comments, std::unordered_map, std::vector>
+operator"" _toml(const char8_t* str, std::size_t len)
+{
+    ::toml::detail::location loc(
+            std::string("TOML literal encoded in a C++ code"),
+            std::vector<char>(reinterpret_cast<const char*>(str),
+                              reinterpret_cast<const char*>(str) + len));
+    return literal_internal_impl(std::move(loc));
+}
+#endif
+
 } // toml_literals
 } // literals
 } // toml

toml/region.hpp

@@ -2,13 +2,14 @@
 // Distributed under the MIT License.
 #ifndef TOML11_REGION_HPP
 #define TOML11_REGION_HPP
-#include "exception.hpp"
 #include <memory>
 #include <vector>
 #include <algorithm>
 #include <initializer_list>
 #include <iterator>
 #include <iomanip>
+#include <cassert>
+#include "color.hpp"
 
 namespace toml
 {
@@ -40,6 +41,7 @@ struct region_base
     region_base& operator=(region_base&&     ) = default;
 
     virtual bool is_ok()           const noexcept {return false;}
+    virtual char front()           const noexcept {return '\0';}
 
     virtual std::string str()      const {return std::string("unknown region");}
     virtual std::string name()     const {return std::string("unknown file");}
@@ -53,9 +55,7 @@ struct region_base
     // number of characters in the line after the region
     virtual std::size_t after()    const noexcept {return 0;}
 
-    virtual std::string comment_before() const {return "";} // just before
-    virtual std::string comment_inline() const {return "";} // in the same line
-    virtual std::string comment()        const {return "";} // concatenate
+    virtual std::vector<std::string> comments() const {return {};}
     // ```toml
     // # comment_before
     // key = "value" # comment_inline
@@ -67,21 +67,21 @@ struct region_base
 //
 // it contains pointer to the file content and iterator that points the current
 // location.
-template<typename Container>
 struct location final : public region_base
 {
-    using const_iterator = typename Container::const_iterator;
-    using source_ptr     = std::shared_ptr<const Container>;
+    using const_iterator  = typename std::vector<char>::const_iterator;
+    using difference_type = typename const_iterator::difference_type;
+    using source_ptr      = std::shared_ptr<const std::vector<char>>;
 
-    static_assert(std::is_same<char, typename Container::value_type>::value,"");
-    static_assert(std::is_same<std::random_access_iterator_tag,
-        typename std::iterator_traits<const_iterator>::iterator_category>::value,
-        "container should be randomly accessible");
-
-    location(std::string name, Container cont)
-      : source_(std::make_shared<Container>(std::move(cont))), line_number_(1),
-        source_name_(std::move(name)), iter_(source_->cbegin())
+    location(std::string name, std::vector<char> cont)
+      : source_(std::make_shared<std::vector<char>>(std::move(cont))),
+        line_number_(1), source_name_(std::move(name)), iter_(source_->cbegin())
     {}
+    location(std::string name, const std::string& cont)
+      : source_(std::make_shared<std::vector<char>>(cont.begin(), cont.end())),
+        line_number_(1), source_name_(std::move(name)), iter_(source_->cbegin())
+    {}
+
     location(const location&) = default;
     location(location&&)      = default;
     location& operator=(const location&) = default;
@@ -89,6 +89,7 @@ struct location final : public region_base
     ~location() = default;
 
     bool is_ok() const noexcept override {return static_cast<bool>(source_);}
+    char front() const noexcept override {return *iter_;}
 
     // this const prohibits codes like `++(loc.iter())`.
     const const_iterator iter()  const noexcept {return iter_;}
@@ -104,15 +105,17 @@ struct location final : public region_base
     // to the location changes the point to look. So an overload of `iter()`
     // which returns mutable reference is removed and `advance()`, `retrace()`
     // and `reset()` is added.
-    void advance(std::size_t n = 1) noexcept
+    void advance(difference_type n = 1) noexcept
     {
-        this->line_number_ += std::count(this->iter_, this->iter_ + n, '\n');
+        this->line_number_ += static_cast<std::size_t>(
+                std::count(this->iter_, std::next(this->iter_, n), '\n'));
         this->iter_ += n;
         return;
     }
-    void retrace(std::size_t n = 1) noexcept
+    void retrace(difference_type n = 1) noexcept
     {
-        this->line_number_ -= std::count(this->iter_ - n, this->iter_, '\n');
+        this->line_number_ -= static_cast<std::size_t>(
+                std::count(std::prev(this->iter_, n), this->iter_, '\n'));
         this->iter_ -= n;
         return;
     }
@@ -122,11 +125,13 @@ struct location final : public region_base
         // iterators and returns a negative value if `first > last`.
         if(0 <= std::distance(rollback, this->iter_)) // rollback < iter
         {
-            this->line_number_ -= std::count(rollback, this->iter_, '\n');
+            this->line_number_ -= static_cast<std::size_t>(
+                    std::count(rollback, this->iter_, '\n'));
         }
         else // iter < rollback [[unlikely]]
         {
-            this->line_number_ += std::count(this->iter_, rollback, '\n');
+            this->line_number_ += static_cast<std::size_t>(
+                    std::count(this->iter_, rollback, '\n'));
         }
         this->iter_ = rollback;
         return;
@@ -163,11 +168,15 @@ struct location final : public region_base
     }
     std::size_t before() const noexcept override
     {
-        return std::distance(this->line_begin(), this->iter());
+        const auto sz = std::distance(this->line_begin(), this->iter());
+        assert(sz >= 0);
+        return static_cast<std::size_t>(sz);
     }
     std::size_t after() const noexcept override
     {
-        return std::distance(this->iter(), this->line_end());
+        const auto sz = std::distance(this->iter(), this->line_end());
+        assert(sz >= 0);
+        return static_cast<std::size_t>(sz);
     }
 
     source_ptr const& source() const& noexcept {return source_;}
@@ -185,33 +194,27 @@ struct location final : public region_base
 //
 // it contains pointer to the file content and iterator that points the first
 // and last location.
-template<typename Container>
 struct region final : public region_base
 {
-    using const_iterator = typename Container::const_iterator;
-    using source_ptr     = std::shared_ptr<const Container>;
-
-    static_assert(std::is_same<char, typename Container::value_type>::value,"");
-    static_assert(std::is_same<std::random_access_iterator_tag,
-        typename std::iterator_traits<const_iterator>::iterator_category>::value,
-        "container should be randomly accessible");
+    using const_iterator = typename std::vector<char>::const_iterator;
+    using source_ptr     = std::shared_ptr<const std::vector<char>>;
 
     // delete default constructor. source_ never be null.
     region() = delete;
 
-    region(const location<Container>& loc)
+    explicit region(const location& loc)
       : source_(loc.source()), source_name_(loc.name()),
         first_(loc.iter()), last_(loc.iter())
     {}
-    region(location<Container>&& loc)
+    explicit region(location&& loc)
       : source_(loc.source()), source_name_(loc.name()),
         first_(loc.iter()), last_(loc.iter())
     {}
 
-    region(const location<Container>& loc, const_iterator f, const_iterator l)
+    region(const location& loc, const_iterator f, const_iterator l)
       : source_(loc.source()), source_name_(loc.name()), first_(f), last_(l)
     {}
-    region(location<Container>&& loc, const_iterator f, const_iterator l)
+    region(location&& loc, const_iterator f, const_iterator l)
       : source_(loc.source()), source_name_(loc.name()), first_(f), last_(l)
     {}
 
@@ -223,16 +226,16 @@ struct region final : public region_base
 
     region& operator+=(const region& other)
     {
-        if(this->begin() != other.begin() || this->end() != other.end() ||
-           this->last_  != other.first_)
-        {
-            throw internal_error("invalid region concatenation");
-        }
+        // different regions cannot be concatenated
+        assert(this->begin() == other.begin() && this->end() == other.end() &&
+               this->last_   == other.first_);
+
         this->last_ = other.last_;
         return *this;
     }
 
     bool is_ok() const noexcept override {return static_cast<bool>(source_);}
+    char front() const noexcept override {return *first_;}
 
     std::string str()  const override {return make_string(first_, last_);}
     std::string line() const override
@@ -251,15 +254,21 @@ struct region final : public region_base
 
     std::size_t size() const noexcept override
     {
-        return std::distance(first_, last_);
+        const auto sz = std::distance(first_, last_);
+        assert(sz >= 0);
+        return static_cast<std::size_t>(sz);
     }
     std::size_t before() const noexcept override
     {
-        return std::distance(this->line_begin(), this->first());
+        const auto sz = std::distance(this->line_begin(), this->first());
+        assert(sz >= 0);
+        return static_cast<std::size_t>(sz);
     }
     std::size_t after() const noexcept override
     {
-        return std::distance(this->last(), this->line_end());
+        const auto sz = std::distance(this->last(), this->line_end());
+        assert(sz >= 0);
+        return static_cast<std::size_t>(sz);
     }
 
     bool contain_newline() const noexcept
@@ -288,92 +297,114 @@ struct region final : public region_base
 
     std::string name() const override {return source_name_;}
 
-    std::string comment_before() const override
+    std::vector<std::string> comments() const override
     {
-        auto iter = this->line_begin(); // points the first element
-        std::vector<std::pair<decltype(iter), decltype(iter)>> comments;
-        while(iter != this->begin())
-        {
-            iter = std::prev(iter);
-            using rev_iter = std::reverse_iterator<decltype(iter)>;
-            auto line_before = std::find(rev_iter(iter), rev_iter(this->begin()),
-                                         '\n').base();
-            // range [line_before, iter) represents the previous line
+        // assuming the current region (`*this`) points a value.
+        // ```toml
+        // a = "value"
+        //     ^^^^^^^- this region
+        // ```
+        using rev_iter = std::reverse_iterator<const_iterator>;
 
-            auto comment_found = std::find(line_before, iter, '#');
-            if(iter != comment_found && std::all_of(line_before, comment_found,
-                    [](const char c) noexcept -> bool {
-                        return c == ' ' || c == '\t';
-                    }))
+        std::vector<std::string> com{};
+        {
+            // find comments just before the current region.
+            // ```toml
+            // # this should be collected.
+            // # this also.
+            // a = value # not this.
+            // ```
+
+            // # this is a comment for `a`, not array elements.
+            // a = [1, 2, 3, 4, 5]
+            if(this->first() == std::find_if(this->line_begin(), this->first(),
+                [](const char c) noexcept -> bool {return c == '[' || c == '{';}))
             {
-                // the line before this range contains only a comment.
-                comments.push_back(std::make_pair(comment_found, iter));
+                auto iter = this->line_begin(); // points the first character
+                while(iter != this->begin())
+                {
+                    iter = std::prev(iter);
+
+                    // range [line_start, iter) represents the previous line
+                    const auto line_start   = std::find(
+                            rev_iter(iter), rev_iter(this->begin()), '\n').base();
+                    const auto comment_found = std::find(line_start, iter, '#');
+                    if(comment_found == iter)
+                    {
+                        break; // comment not found.
+                    }
+
+                    // exclude the following case.
+                    // > a = "foo" # comment // <-- this is not a comment for b but a.
+                    // > b = "current value"
+                    if(std::all_of(line_start, comment_found,
+                            [](const char c) noexcept -> bool {
+                                return c == ' ' || c == '\t';
+                            }))
+                    {
+                        // unwrap the first '#' by std::next.
+                        auto str = make_string(std::next(comment_found), iter);
+                        if(!str.empty() && str.back() == '\r') {str.pop_back();}
+                        com.push_back(std::move(str));
+                    }
+                    else
+                    {
+                        break;
+                    }
+                    iter = line_start;
+                }
             }
-            else
-            {
-                break;
-            }
-            iter = line_before;
         }
 
-        std::string com;
-        for(auto i = comments.crbegin(), e = comments.crend(); i!=e; ++i)
+        if(com.size() > 1)
         {
-            if(i != comments.crbegin()) {com += '\n';}
-            com += std::string(i->first, i->second);
+            std::reverse(com.begin(), com.end());
+        }
+
+        {
+            // find comments just after the current region.
+            // ```toml
+            // # not this.
+            // a = value # this one.
+            // a = [ # not this (technically difficult)
+            //
+            // ] # and this.
+            // ```
+            // The reason why it's difficult is that it requires parsing in the
+            // following case.
+            // ```toml
+            // a = [ 10 # this comment is for `10`. not for `a` but `a[0]`.
+            // # ...
+            // ] # this is apparently a comment for a.
+            //
+            // b = [
+            // 3.14 ] # there is no way to add a comment to `3.14` currently.
+            //
+            // c = [
+            //   3.14 # do this if you need a comment here.
+            // ]
+            // ```
+            const auto comment_found =
+                std::find(this->last(), this->line_end(), '#');
+            if(comment_found != this->line_end()) // '#' found
+            {
+                // table = {key = "value"} # what is this for?
+                // the above comment is not for "value", but {key="value"}.
+                if(comment_found == std::find_if(this->last(), comment_found,
+                    [](const char c) noexcept -> bool {
+                        return !(c == ' ' || c == '\t' || c == ',');
+                    }))
+                {
+                    // unwrap the first '#' by std::next.
+                    auto str = make_string(std::next(comment_found), this->line_end());
+                    if(!str.empty() && str.back() == '\r') {str.pop_back();}
+                    com.push_back(std::move(str));
+                }
+            }
         }
         return com;
     }
 
-    std::string comment_inline() const override
-    {
-        if(this->contain_newline())
-        {
-            std::string com;
-            // check both the first and the last line.
-            const auto first_line_end =
-                std::find(this->line_begin(), this->last(), '\n');
-            const auto first_comment_found =
-                std::find(this->line_begin(), first_line_end, '#');
-
-            if(first_comment_found != first_line_end)
-            {
-                com += std::string(first_comment_found, first_line_end);
-            }
-
-            const auto last_comment_found =
-                std::find(this->last(), this->line_end(), '#');
-            if(last_comment_found != this->line_end())
-            {
-                if(!com.empty()){com += '\n';}
-                com += std::string(last_comment_found, this->line_end());
-            }
-            return com;
-        }
-        const auto comment_found =
-            std::find(this->line_begin(), this->line_end(), '#');
-        return std::string(comment_found, this->line_end());
-    }
-
-    std::string comment() const override
-    {
-        std::string com_bef = this->comment_before();
-        std::string com_inl = this->comment_inline();
-        if(!com_bef.empty() && !com_inl.empty())
-        {
-            com_bef += '\n';
-            return com_bef + com_inl;
-        }
-        else if(com_bef.empty())
-        {
-            return com_inl;
-        }
-        else
-        {
-            return com_bef;
-        }
-    }
-
   private:
 
     source_ptr     source_;
@@ -381,85 +412,6 @@ struct region final : public region_base
     const_iterator first_, last_;
 };
 
-// to show a better error message.
-inline std::string format_underline(const std::string& message,
-        std::vector<std::pair<region_base const*, std::string>> reg_com,
-        std::vector<std::string> helps = {})
-{
-    assert(!reg_com.empty());
-
-#ifdef _WIN32
-    const auto newline = "\r\n";
-#else
-    const char newline = '\n';
-#endif
-
-    const auto line_num_width = std::max_element(reg_com.begin(), reg_com.end(),
-        [](std::pair<region_base const*, std::string> const& lhs,
-           std::pair<region_base const*, std::string> const& rhs)
-        {
-            return lhs.first->line_num().size() < rhs.first->line_num().size();
-        }
-    )->first->line_num().size();
-
-    std::ostringstream retval;
-    retval << message << newline;
-
-    for(std::size_t i=0; i<reg_com.size(); ++i)
-    {
-        if(i!=0 && reg_com.at(i-1).first->name() == reg_com.at(i).first->name())
-        {
-            retval << newline << " ..." << newline;
-        }
-        else
-        {
-            if(i != 0) {retval << newline;}
-            retval << " --> " << reg_com.at(i).first->name() << newline;
-        }
-
-        const region_base* const reg = reg_com.at(i).first;
-        const std::string&   comment = reg_com.at(i).second;
-
-
-        retval << ' ' << std::setw(line_num_width) << reg->line_num();
-        retval << " | " << reg->line() << newline;
-        retval << make_string(line_num_width + 1, ' ');
-        retval << " | " << make_string(reg->before(), ' ');
-
-        if(reg->size() == 1)
-        {
-            // invalid
-            // ^------
-            retval << '^';
-            retval << make_string(reg->after(), '-');
-        }
-        else
-        {
-            // invalid
-            // ~~~~~~~
-            const auto underline_len = std::min(reg->size(), reg->line().size());
-            retval << make_string(underline_len, '~');
-        }
-
-        retval << ' ';
-        retval << comment;
-    }
-
-    if(helps.size() != 0)
-    {
-        retval << newline;
-        retval << make_string(line_num_width + 1, ' ');
-        retval << " | ";
-        for(const auto help : helps)
-        {
-            retval << newline;
-            retval << "Hint: ";
-            retval << help;
-        }
-    }
-    return retval.str();
-}
-
 } // detail
 } // toml
 #endif// TOML11_REGION_H

toml/serializer.hpp

@@ -2,82 +2,167 @@
 // Distributed under the MIT License.
 #ifndef TOML11_SERIALIZER_HPP
 #define TOML11_SERIALIZER_HPP
-#include "value.hpp"
-#include "lexer.hpp"
-#include <limits>
 #include <cstdio>
 
+#include <limits>
+
+#include "lexer.hpp"
+#include "value.hpp"
+
 namespace toml
 {
 
+// This function serialize a key. It checks a string is a bare key and
+// escapes special characters if the string is not compatible to a bare key.
+// ```cpp
+// std::string k("non.bare.key"); // the key itself includes `.`s.
+// std::string formatted = toml::format_key(k);
+// assert(formatted == "\"non.bare.key\"");
+// ```
+//
+// This function is exposed to make it easy to write a user-defined serializer.
+// Since toml restricts characters available in a bare key, generally a string
+// should be escaped. But checking whether a string needs to be surrounded by
+// a `"` and escaping some special character is boring.
+template<typename charT, typename traits, typename Alloc>
+std::basic_string<charT, traits, Alloc>
+format_key(const std::basic_string<charT, traits, Alloc>& key)
+{
+    // check the key can be a bare (unquoted) key
+    detail::location loc(key, std::vector<char>(key.begin(), key.end()));
+    detail::lex_unquoted_key::invoke(loc);
+    if(loc.iter() == loc.end())
+    {
+        return key; // all the tokens are consumed. the key is unquoted-key.
+    }
+
+    //if it includes special characters, then format it in a "quoted" key.
+    std::basic_string<charT, traits, Alloc> serialized("\"");
+    for(const char c : key)
+    {
+        switch(c)
+        {
+            case '\\': {serialized += "\\\\"; break;}
+            case '\"': {serialized += "\\\""; break;}
+            case '\b': {serialized += "\\b";  break;}
+            case '\t': {serialized += "\\t";  break;}
+            case '\f': {serialized += "\\f";  break;}
+            case '\n': {serialized += "\\n";  break;}
+            case '\r': {serialized += "\\r";  break;}
+            default  : {serialized += c;      break;}
+        }
+    }
+    serialized += "\"";
+    return serialized;
+}
+
+template<typename charT, typename traits, typename Alloc>
+std::basic_string<charT, traits, Alloc>
+format_keys(const std::vector<std::basic_string<charT, traits, Alloc>>& keys)
+{
+    std::basic_string<charT, traits, Alloc> serialized;
+    if(keys.empty()) {return serialized;}
+
+    for(const auto& ky : keys)
+    {
+        serialized += format_key(ky);
+        serialized += charT('.');
+    }
+    serialized.pop_back(); // remove the last dot '.'
+    return serialized;
+}
+
+template<typename Value>
 struct serializer
 {
-    serializer(const std::size_t w              = 80,
+    static_assert(detail::is_basic_value<Value>::value,
+                  "toml::serializer is for toml::value and its variants, "
+                  "toml::basic_value<...>.");
+
+    using value_type           = Value;
+    using key_type             = typename value_type::key_type            ;
+    using comment_type         = typename value_type::comment_type        ;
+    using boolean_type         = typename value_type::boolean_type        ;
+    using integer_type         = typename value_type::integer_type        ;
+    using floating_type        = typename value_type::floating_type       ;
+    using string_type          = typename value_type::string_type         ;
+    using local_time_type      = typename value_type::local_time_type     ;
+    using local_date_type      = typename value_type::local_date_type     ;
+    using local_datetime_type  = typename value_type::local_datetime_type ;
+    using offset_datetime_type = typename value_type::offset_datetime_type;
+    using array_type           = typename value_type::array_type          ;
+    using table_type           = typename value_type::table_type          ;
+
+    serializer(const std::size_t w              = 80u,
                const int         float_prec     = std::numeric_limits<toml::floating>::max_digits10,
                const bool        can_be_inlined = false,
-               std::vector<toml::key> ks        = {})
-        : can_be_inlined_(can_be_inlined), float_prec_(float_prec), width_(w),
-          keys_(std::move(ks))
+               const bool        no_comment     = false,
+               std::vector<toml::key> ks        = {},
+               const bool     value_has_comment = false)
+        : can_be_inlined_(can_be_inlined), no_comment_(no_comment),
+          value_has_comment_(value_has_comment && !no_comment),
+          float_prec_(float_prec), width_(w), keys_(std::move(ks))
     {}
     ~serializer() = default;
 
-    std::string operator()(const toml::boolean& b) const
+    std::string operator()(const boolean_type& b) const
     {
         return b ? "true" : "false";
     }
-    std::string operator()(const integer i) const
+    std::string operator()(const integer_type i) const
     {
         return std::to_string(i);
     }
-    std::string operator()(const toml::floating f) const
+    std::string operator()(const floating_type f) const
     {
         const auto fmt = "%.*g";
         const auto bsz = std::snprintf(nullptr, 0, fmt, this->float_prec_, f);
-        std::vector<char> buf(bsz + 1, '\0'); // +1 for null character(\0)
+        // +1 for null character(\0)
+        std::vector<char> buf(static_cast<std::size_t>(bsz + 1), '\0');
         std::snprintf(buf.data(), buf.size(), fmt, this->float_prec_, f);
 
         std::string token(buf.begin(), std::prev(buf.end()));
-        if(token.back() == '.') // 1. => 1.0
+        if(!token.empty() && token.back() == '.') // 1. => 1.0
         {
             token += '0';
         }
-        const auto e = std::find_if(token.cbegin(), token.cend(),
-            [](const char c) -> bool {
-                return c == 'E' || c == 'e';
-            });
-        if(e == token.cend())
-        {
-            return token; // there is no exponent part. just return it.
-        }
 
-        // zero-prefix in an exponent is not allowed in TOML.
-        // remove it if it exists.
-        bool        sign_exists = false;
-        std::size_t zero_prefix = 0;
-        for(auto iter = std::next(e), iend = token.cend(); iter != iend; ++iter)
+        const auto e = std::find_if(
+            token.cbegin(), token.cend(), [](const char c) noexcept -> bool {
+                return c == 'e' || c == 'E';
+            });
+        const auto has_exponent = (token.cend() != e);
+        const auto has_fraction = (token.cend() != std::find(
+            token.cbegin(), token.cend(), '.'));
+
+        if(!has_exponent && !has_fraction)
         {
-            if(*iter == '+' || *iter == '-'){sign_exists = true; continue;}
-            if(*iter == '0'){zero_prefix += 1;}
-            else {break;}
-        }
-        if(zero_prefix != 0)
-        {
-            const auto offset = std::distance(token.cbegin(), e) +
-                               (sign_exists ? 2 : 1);
-            token.erase(offset, zero_prefix);
+            // the resulting value does not have any float specific part!
+            token += ".0";
         }
         return token;
     }
-    std::string operator()(const string& s) const
+    std::string operator()(const string_type& s) const
     {
         if(s.kind == string_t::basic)
         {
-            if(std::find(s.str.cbegin(), s.str.cend(), '\n') != s.str.cend())
+            if(std::find(s.str.cbegin(), s.str.cend(), '\n') != s.str.cend() ||
+               std::find(s.str.cbegin(), s.str.cend(), '\"') != s.str.cend())
             {
-                // if linefeed is contained, make it multiline-string.
-                const std::string open("\"\"\"\n");
-                const std::string close("\\\n\"\"\"");
-                return open + this->escape_ml_basic_string(s.str) + close;
+                // if linefeed or double-quote is contained,
+                // make it multiline basic string.
+                const auto escaped = this->escape_ml_basic_string(s.str);
+                std::string open("\"\"\"");
+                std::string close("\"\"\"");
+                if(escaped.find('\n') != std::string::npos ||
+                   this->width_ < escaped.size() + 6)
+                {
+                    // if the string body contains newline or is enough long,
+                    // add newlines after and before delimiters.
+                    open += "\n";
+                    close = std::string("\\\n") + close;
+                }
+                return open + escaped + close;
             }
 
             // no linefeed. try to make it oneline-string.
@@ -118,7 +203,11 @@ struct serializer
             if(std::find(s.str.cbegin(), s.str.cend(), '\n') != s.str.cend() ||
                std::find(s.str.cbegin(), s.str.cend(), '\'') != s.str.cend() )
             {
-                const std::string open("'''\n");
+                std::string open("'''");
+                if(this->width_ + 6 < s.str.size())
+                {
+                    open += '\n'; // the first newline is ignored by TOML spec
+                }
                 const std::string close("'''");
                 return open + s.str + close;
             }
@@ -130,85 +219,45 @@ struct serializer
         }
     }
 
-    std::string operator()(const local_date& d) const
+    std::string operator()(const local_date_type& d) const
     {
         std::ostringstream oss;
         oss << d;
         return oss.str();
     }
-    std::string operator()(const local_time& t) const
+    std::string operator()(const local_time_type& t) const
     {
         std::ostringstream oss;
         oss << t;
         return oss.str();
     }
-    std::string operator()(const local_datetime& dt) const
+    std::string operator()(const local_datetime_type& dt) const
     {
         std::ostringstream oss;
         oss << dt;
         return oss.str();
     }
-    std::string operator()(const offset_datetime& odt) const
+    std::string operator()(const offset_datetime_type& odt) const
     {
         std::ostringstream oss;
         oss << odt;
         return oss.str();
     }
 
-    std::string operator()(const array& v) const
+    std::string operator()(const array_type& v) const
     {
-        if(!v.empty() && v.front().is_table())// v is an array of tables
-        {
-            // if it's not inlined, we need to add `[[table.key]]`.
-            // but if it can be inlined, we need `table.key = [...]`.
-            if(this->can_be_inlined_)
-            {
-                std::string token;
-                if(!keys_.empty())
-                {
-                    token += this->serialize_key(keys_.back());
-                    token += " = ";
-                }
-                bool width_exceeds = false;
-                token += "[\n";
-                for(const auto& item : v)
-                {
-                    const auto t =
-                        this->make_inline_table(item.cast<value_t::Table>());
-
-                    if(t.size() + 1 > width_ || // +1 for the last comma {...},
-                       std::find(t.cbegin(), t.cend(), '\n') != t.cend())
-                    {
-                        width_exceeds = true;
-                        break;
-                    }
-                    token += t;
-                    token += ",\n";
-                }
-                if(!width_exceeds)
-                {
-                    token += "]\n";
-                    return token;
-                }
-                // if width_exceeds, serialize it as [[array.of.tables]].
-            }
-
-            std::string token;
-            for(const auto& item : v)
-            {
-                token += "[[";
-                token += this->serialize_dotted_key(keys_);
-                token += "]]\n";
-                token += this->make_multiline_table(item.cast<value_t::Table>());
-            }
-            return token;
-        }
         if(v.empty())
         {
             return std::string("[]");
         }
+        if(this->is_array_of_tables(v))
+        {
+            return make_array_of_tables(v);
+        }
 
-        // not an array of tables. normal array. first, try to make it inline.
+        // not an array of tables. normal array.
+        // first, try to make it inline if none of the elements have a comment.
+        if( ! this->has_comment_inside(v))
         {
             const auto inl = this->make_inline_array(v);
             if(inl.size() < this->width_ &&
@@ -218,16 +267,54 @@ struct serializer
             }
         }
 
-        // if the length exceeds this->width_, print multiline array
+        // if the length exceeds this->width_, print multiline array.
+        // key = [
+        //   # ...
+        //   42,
+        //   ...
+        // ]
         std::string token;
         std::string current_line;
         token += "[\n";
         for(const auto& item : v)
         {
-            auto next_elem = toml::visit(*this, item);
-            // newline between array-value and comma is not allowed
-            if(next_elem.back() == '\n'){next_elem.pop_back();}
+            if( ! item.comments().empty() && !no_comment_)
+            {
+                // if comment exists, the element must be the only element in the line.
+                // e.g. the following is not allowed.
+                // ```toml
+                // array = [
+                // # comment for what?
+                // 1, 2, 3, 4, 5
+                // ]
+                // ```
+                if(!current_line.empty())
+                {
+                    if(current_line.back() != '\n')
+                    {
+                        current_line += '\n';
+                    }
+                    token += current_line;
+                    current_line.clear();
+                }
+                for(const auto& c : item.comments())
+                {
+                    token += '#';
+                    token += c;
+                    token += '\n';
+                }
+                token += toml::visit(*this, item);
+                if(!token.empty() && token.back() == '\n') {token.pop_back();}
+                token += ",\n";
+                continue;
+            }
+            std::string next_elem;
+            next_elem += toml::visit(*this, item);
 
+            // comma before newline.
+            if(!next_elem.empty() && next_elem.back() == '\n') {next_elem.pop_back();}
+
+            // if current line does not exceeds the width limit, continue.
             if(current_line.size() + next_elem.size() + 1 < this->width_)
             {
                 current_line += next_elem;
@@ -235,12 +322,13 @@ struct serializer
             }
             else if(current_line.empty())
             {
-                // the next elem cannot be within the width.
+                // if current line was empty, force put the next_elem because
+                // next_elem is not splittable
                 token += next_elem;
                 token += ",\n";
-                // keep current line empty
+                // current_line is kept empty
             }
-            else // current_line has some tokens and it exceeds width
+            else // reset current_line
             {
                 assert(current_line.back() == ',');
                 token += current_line;
@@ -251,25 +339,32 @@ struct serializer
         }
         if(!current_line.empty())
         {
-            if(current_line.back() != '\n') {current_line += '\n';}
+            if(!current_line.empty() && current_line.back() != '\n')
+            {
+                current_line += '\n';
+            }
             token += current_line;
         }
         token += "]\n";
         return token;
     }
 
-    std::string operator()(const table& v) const
+    // templatize for any table-like container
+    std::string operator()(const table_type& v) const
     {
-        if(this->can_be_inlined_)
+        // if an element has a comment, then it can't be inlined.
+        // table = {# how can we write a comment for this? key = "value"}
+        if(this->can_be_inlined_ && !(this->has_comment_inside(v)))
         {
             std::string token;
             if(!this->keys_.empty())
             {
-                token += this->serialize_key(this->keys_.back());
+                token += format_key(this->keys_.back());
                 token += " = ";
             }
             token += this->make_inline_table(v);
-            if(token.size() < this->width_)
+            if(token.size() < this->width_ &&
+               token.end() == std::find(token.begin(), token.end(), '\n'))
             {
                 return token;
             }
@@ -279,7 +374,7 @@ struct serializer
         if(!keys_.empty())
         {
             token += '[';
-            token += this->serialize_dotted_key(keys_);
+            token += format_keys(keys_);
             token += "]\n";
         }
         token += this->make_multiline_table(v);
@@ -288,34 +383,6 @@ struct serializer
 
   private:
 
-    std::string serialize_key(const toml::key& key) const
-    {
-        detail::location<toml::key> loc(key, key);
-        detail::lex_unquoted_key::invoke(loc);
-        if(loc.iter() == loc.end())
-        {
-            return key; // all the tokens are consumed. the key is unquoted-key.
-        }
-        std::string token("\"");
-        token += this->escape_basic_string(key);
-        token += "\"";
-        return token;
-    }
-
-    std::string serialize_dotted_key(const std::vector<toml::key>& keys) const
-    {
-        std::string token;
-        if(keys.empty()){return token;}
-
-        for(const auto& k : keys)
-        {
-            token += this->serialize_key(k);
-            token += '.';
-        }
-        token.erase(token.size() - 1, 1); // remove trailing `.`
-        return token;
-    }
-
     std::string escape_basic_string(const std::string& s) const
     {
         //XXX assuming `s` is a valid utf-8 sequence.
@@ -345,7 +412,9 @@ struct serializer
             switch(*i)
             {
                 case '\\': {retval += "\\\\"; break;}
-                case '\"': {retval += "\\\""; break;}
+                // One or two consecutive "s are allowed.
+                // Later we will check there are no three consecutive "s.
+                //   case '\"': {retval += "\\\""; break;}
                 case '\b': {retval += "\\b";  break;}
                 case '\t': {retval += "\\t";  break;}
                 case '\f': {retval += "\\f";  break;}
@@ -366,26 +435,71 @@ struct serializer
                 default: {retval += *i; break;}
             }
         }
+        // Only 1 or 2 consecutive `"`s are allowed in multiline basic string.
+        // 3 consecutive `"`s are considered as a closing delimiter.
+        // We need to check if there are 3 or more consecutive `"`s and insert
+        // backslash to break them down into several short `"`s like the `str6`
+        // in the following example.
+        // ```toml
+        // str4 = """Here are two quotation marks: "". Simple enough."""
+        // # str5 = """Here are three quotation marks: """."""  # INVALID
+        // str5 = """Here are three quotation marks: ""\"."""
+        // str6 = """Here are fifteen quotation marks: ""\"""\"""\"""\"""\"."""
+        // ```
+        auto found_3_quotes = retval.find("\"\"\"");
+        while(found_3_quotes != std::string::npos)
+        {
+            retval.replace(found_3_quotes, 3, "\"\"\\\"");
+            found_3_quotes = retval.find("\"\"\"");
+        }
         return retval;
     }
 
-    std::string make_inline_array(const array& v) const
+    // if an element of a table or an array has a comment, it cannot be inlined.
+    bool has_comment_inside(const array_type& a) const noexcept
     {
+        // if no_comment is set, comments would not be written.
+        if(this->no_comment_) {return false;}
+
+        for(const auto& v : a)
+        {
+            if(!v.comments().empty()) {return true;}
+        }
+        return false;
+    }
+    bool has_comment_inside(const table_type& t) const noexcept
+    {
+        // if no_comment is set, comments would not be written.
+        if(this->no_comment_) {return false;}
+
+        for(const auto& kv : t)
+        {
+            if(!kv.second.comments().empty()) {return true;}
+        }
+        return false;
+    }
+
+    std::string make_inline_array(const array_type& v) const
+    {
+        assert(!has_comment_inside(v));
         std::string token;
         token += '[';
         bool is_first = true;
         for(const auto& item : v)
         {
             if(is_first) {is_first = false;} else {token += ',';}
-            token += visit(serializer(std::numeric_limits<std::size_t>::max(),
-                                      this->float_prec_, true), item);
+            token += visit(serializer(
+                (std::numeric_limits<std::size_t>::max)(), this->float_prec_,
+                /* inlined */ true, /*no comment*/ false, /*keys*/ {},
+                /*has_comment*/ !item.comments().empty()), item);
         }
         token += ']';
         return token;
     }
 
-    std::string make_inline_table(const table& v) const
+    std::string make_inline_table(const table_type& v) const
     {
+        assert(!has_comment_inside(v));
         assert(this->can_be_inlined_);
         std::string token;
         token += '{';
@@ -394,34 +508,48 @@ struct serializer
         {
             // in inline tables, trailing comma is not allowed (toml-lang #569).
             if(is_first) {is_first = false;} else {token += ',';}
-            token += this->serialize_key(kv.first);
+            token += format_key(kv.first);
             token += '=';
-            token += visit(serializer(std::numeric_limits<std::size_t>::max(),
-                                      this->float_prec_, true), kv.second);
+            token += visit(serializer(
+                (std::numeric_limits<std::size_t>::max)(), this->float_prec_,
+                /* inlined */ true, /*no comment*/ false, /*keys*/ {},
+                /*has_comment*/ !kv.second.comments().empty()), kv.second);
         }
         token += '}';
         return token;
     }
 
-    std::string make_multiline_table(const table& v) const
+    std::string make_multiline_table(const table_type& v) const
     {
         std::string token;
 
-        // print non-table stuff first. because after printing [foo.bar], the
-        // remaining non-table values will be assigned into [foo.bar], not [foo]
-        for(const auto kv : v)
+        // print non-table elements first.
+        // ```toml
+        // [foo]         # a table we're writing now here
+        // key = "value" # <- non-table element, "key"
+        // # ...
+        // [foo.bar] # <- table element, "bar"
+        // ```
+        // because after printing [foo.bar], the remaining non-table values will
+        // be assigned into [foo.bar], not [foo]. Those values should be printed
+        // earlier.
+        for(const auto& kv : v)
         {
             if(kv.second.is_table() || is_array_of_tables(kv.second))
             {
                 continue;
             }
 
-            const auto key_and_sep    = this->serialize_key(kv.first) + " = ";
+            token += write_comments(kv.second);
+
+            const auto key_and_sep    = format_key(kv.first) + " = ";
             const auto residual_width = (this->width_ > key_and_sep.size()) ?
                                         this->width_ - key_and_sep.size() : 0;
             token += key_and_sep;
-            token += visit(serializer(residual_width, this->float_prec_, true),
-                           kv.second);
+            token += visit(serializer(residual_width, this->float_prec_,
+                /*can be inlined*/ true, /*no comment*/ false, /*keys*/ {},
+                /*has_comment*/ !kv.second.comments().empty()), kv.second);
+
             if(token.back() != '\n')
             {
                 token += '\n';
@@ -446,9 +574,9 @@ struct serializer
             std::vector<toml::key> ks(this->keys_);
             ks.push_back(kv.first);
 
-            auto tmp = visit(serializer(
-                this->width_, this->float_prec_, !multiline_table_printed, ks),
-                kv.second);
+            auto tmp = visit(serializer(this->width_, this->float_prec_,
+                !multiline_table_printed, this->no_comment_, ks,
+                /*has_comment*/ !kv.second.comments().empty()), kv.second);
 
             if((!multiline_table_printed) &&
                std::find(tmp.cbegin(), tmp.cend(), '\n') != tmp.cend())
@@ -460,65 +588,248 @@ struct serializer
                 // still inline tables only.
                 tmp += '\n';
             }
+
+            token += write_comments(kv.second);
             token += tmp;
         }
         return token;
     }
 
-    bool is_array_of_tables(const value& v) const
+    std::string make_array_of_tables(const array_type& v) const
     {
-        if(!v.is_array()) {return false;}
-        const auto& a = v.as_array();
-        return !a.empty() && a.front().is_table();
+        // if it's not inlined, we need to add `[[table.key]]`.
+        // but if it can be inlined, we can format it as the following.
+        // ```
+        // table.key = [
+        //   {...},
+        //   # comment
+        //   {...},
+        // ]
+        // ```
+        // This function checks if inlinization is possible or not, and then
+        // format the array-of-tables in a proper way.
+        //
+        // Note about comments:
+        //
+        // If the array itself has a comment (value_has_comment_ == true), we
+        // should try to make it inline.
+        // ```toml
+        // # comment about array
+        // array = [
+        //   # comment about table element
+        //   {of = "table"}
+        // ]
+        // ```
+        // If it is formatted as a multiline table, the two comments becomes
+        // indistinguishable.
+        // ```toml
+        // # comment about array
+        // # comment about table element
+        // [[array]]
+        // of = "table"
+        // ```
+        // So we need to try to make it inline, and it force-inlines regardless
+        // of the line width limit.
+        //     It may fail if the element of a table has comment. In that case,
+        // the array-of-tables will be formatted as a multiline table.
+        if(this->can_be_inlined_ || this->value_has_comment_)
+        {
+            std::string token;
+            if(!keys_.empty())
+            {
+                token += format_key(keys_.back());
+                token += " = ";
+            }
+
+            bool failed = false;
+            token += "[\n";
+            for(const auto& item : v)
+            {
+                // if an element of the table has a comment, the table
+                // cannot be inlined.
+                if(this->has_comment_inside(item.as_table()))
+                {
+                    failed = true;
+                    break;
+                }
+                // write comments for the table itself
+                token += write_comments(item);
+
+                const auto t = this->make_inline_table(item.as_table());
+
+                if(t.size() + 1 > width_ || // +1 for the last comma {...},
+                   std::find(t.cbegin(), t.cend(), '\n') != t.cend())
+                {
+                    // if the value itself has a comment, ignore the line width limit
+                    if( ! this->value_has_comment_)
+                    {
+                        failed = true;
+                        break;
+                    }
+                }
+                token += t;
+                token += ",\n";
+            }
+
+            if( ! failed)
+            {
+                token += "]\n";
+                return token;
+            }
+            // if failed, serialize them as [[array.of.tables]].
+        }
+
+        std::string token;
+        for(const auto& item : v)
+        {
+            token += write_comments(item);
+            token += "[[";
+            token += format_keys(keys_);
+            token += "]]\n";
+            token += this->make_multiline_table(item.as_table());
+        }
+        return token;
+    }
+
+    std::string write_comments(const value_type& v) const
+    {
+        std::string retval;
+        if(this->no_comment_) {return retval;}
+
+        for(const auto& c : v.comments())
+        {
+            retval += '#';
+            retval += c;
+            retval += '\n';
+        }
+        return retval;
+    }
+
+    bool is_array_of_tables(const value_type& v) const
+    {
+        if(!v.is_array() || v.as_array().empty()) {return false;}
+        return is_array_of_tables(v.as_array());
+    }
+    bool is_array_of_tables(const array_type& v) const
+    {
+        // Since TOML v0.5.0, heterogeneous arrays are allowed. So we need to
+        // check all the element in an array to check if the array is an array
+        // of tables.
+        return std::all_of(v.begin(), v.end(), [](const value_type& elem) {
+                return elem.is_table();
+            });
     }
 
   private:
 
     bool        can_be_inlined_;
+    bool        no_comment_;
+    bool        value_has_comment_;
     int         float_prec_;
     std::size_t width_;
     std::vector<toml::key> keys_;
 };
 
-inline std::string
-format(const value& v, std::size_t w = 80,
+template<typename C,
+         template<typename ...> class M, template<typename ...> class V>
+std::string
+format(const basic_value<C, M, V>& v, std::size_t w = 80u,
        int fprec = std::numeric_limits<toml::floating>::max_digits10,
-       bool force_inline = false)
+       bool no_comment = false, bool force_inline = false)
 {
+    using value_type = basic_value<C, M, V>;
     // if value is a table, it is considered to be a root object.
-    // the root object can't be an inline table. so pass false. otherwise, true.
-    return visit(serializer(w, fprec, (!v.is_table()) || force_inline), v);
+    // the root object can't be an inline table.
+    if(v.is_table())
+    {
+        std::ostringstream oss;
+        if(!v.comments().empty())
+        {
+            oss << v.comments();
+            oss << '\n'; // to split the file comment from the first element
+        }
+        const auto serialized = visit(serializer<value_type>(w, fprec, no_comment, false), v);
+        oss << serialized;
+        return oss.str();
+    }
+    return visit(serializer<value_type>(w, fprec, force_inline), v);
 }
-inline std::string
-format(const table& t, std::size_t w = 80,
-       int fprec = std::numeric_limits<toml::floating>::max_digits10,
-       bool force_inline = false)
+
+namespace detail
 {
-    return serializer(w, fprec, force_inline)(t);
+template<typename charT, typename traits>
+int comment_index(std::basic_ostream<charT, traits>&)
+{
+    static const int index = std::ios_base::xalloc();
+    return index;
+}
+} // detail
+
+template<typename charT, typename traits>
+std::basic_ostream<charT, traits>&
+nocomment(std::basic_ostream<charT, traits>& os)
+{
+    // by default, it is zero. and by defalut, it shows comments.
+    os.iword(detail::comment_index(os)) = 1;
+    return os;
 }
 
 template<typename charT, typename traits>
 std::basic_ostream<charT, traits>&
-operator<<(std::basic_ostream<charT, traits>& os, const value& v)
+showcomment(std::basic_ostream<charT, traits>& os)
 {
-    // get status of std::setw().
-    const std::size_t w     = os.width();
-    const int         fprec = os.precision();
-    os.width(0);
-    // the root object can't be an inline table. so pass `false`.
-    os << visit(serializer(w, fprec, false), v);
+    // by default, it is zero. and by defalut, it shows comments.
+    os.iword(detail::comment_index(os)) = 0;
     return os;
 }
-template<typename charT, typename traits>
+
+template<typename charT, typename traits, typename C,
+         template<typename ...> class M, template<typename ...> class V>
 std::basic_ostream<charT, traits>&
-operator<<(std::basic_ostream<charT, traits>& os, const table& v)
+operator<<(std::basic_ostream<charT, traits>& os, const basic_value<C, M, V>& v)
 {
+    using value_type = basic_value<C, M, V>;
+
     // get status of std::setw().
-    const std::size_t w     = os.width();
-    const int         fprec = os.precision();
+    const auto w     = static_cast<std::size_t>(os.width());
+    const int  fprec = static_cast<int>(os.precision());
     os.width(0);
+
+    // by defualt, iword is initialized byl 0. And by default, toml11 outputs
+    // comments. So `0` means showcomment. 1 means nocommnet.
+    const bool no_comment = (1 == os.iword(detail::comment_index(os)));
+
+    if(!no_comment && v.is_table() && !v.comments().empty())
+    {
+        os << v.comments();
+        os << '\n'; // to split the file comment from the first element
+    }
     // the root object can't be an inline table. so pass `false`.
-    os << serializer(w, fprec, false)(v);
+    const auto serialized = visit(serializer<value_type>(w, fprec, no_comment, false), v);
+    os << serialized;
+
+    // if v is a non-table value, and has only one comment, then
+    // put a comment just after a value. in the following way.
+    //
+    // ```toml
+    // key = "value" # comment.
+    // ```
+    //
+    // Since the top-level toml object is a table, one who want to put a
+    // non-table toml value must use this in a following way.
+    //
+    // ```cpp
+    // toml::value v;
+    // std::cout << "user-defined-key = " << v << std::endl;
+    // ```
+    //
+    // In this case, it is impossible to put comments before key-value pair.
+    // The only way to preserve comments is to put all of them after a value.
+    if(!no_comment && !v.is_table() && !v.comments().empty())
+    {
+        os << " #";
+        for(const auto& c : v.comments()) {os << c;}
+    }
     return os;
 }
 

toml/source_location.hpp

@@ -0,0 +1,233 @@
+//     Copyright Toru Niina 2019.
+// Distributed under the MIT License.
+#ifndef TOML11_SOURCE_LOCATION_HPP
+#define TOML11_SOURCE_LOCATION_HPP
+#include <cstdint>
+#include <sstream>
+
+#include "region.hpp"
+
+namespace toml
+{
+
+// A struct to contain location in a toml file.
+// The interface imitates std::experimental::source_location,
+// but not completely the same.
+//
+// It would be constructed by toml::value. It can be used to generate
+// user-defined error messages.
+//
+// - std::uint_least32_t line() const noexcept
+//   - returns the line number where the region is on.
+// - std::uint_least32_t column() const noexcept
+//   - returns the column number where the region starts.
+// - std::uint_least32_t region() const noexcept
+//   - returns the size of the region.
+//
+// +-- line()       +-- region of interest (region() == 9)
+// v            .---+---.
+// 12 | value = "foo bar"
+//              ^
+//              +-- column()
+//
+// - std::string const& file_name() const noexcept;
+//   - name of the file.
+// - std::string const& line_str() const noexcept;
+//   - the whole line that contains the region of interest.
+//
+struct source_location
+{
+  public:
+
+    source_location()
+        : line_num_(1), column_num_(1), region_size_(1),
+          file_name_("unknown file"), line_str_("")
+    {}
+
+    explicit source_location(const detail::region_base* reg)
+        : line_num_(1), column_num_(1), region_size_(1),
+          file_name_("unknown file"), line_str_("")
+    {
+        if(reg)
+        {
+            if(reg->line_num() != detail::region_base().line_num())
+            {
+                line_num_ = static_cast<std::uint_least32_t>(
+                        std::stoul(reg->line_num()));
+            }
+            column_num_  = static_cast<std::uint_least32_t>(reg->before() + 1);
+            region_size_ = static_cast<std::uint_least32_t>(reg->size());
+            file_name_   = reg->name();
+            line_str_    = reg->line();
+        }
+    }
+
+    explicit source_location(const detail::region& reg)
+        : line_num_(static_cast<std::uint_least32_t>(std::stoul(reg.line_num()))),
+          column_num_(static_cast<std::uint_least32_t>(reg.before() + 1)),
+          region_size_(static_cast<std::uint_least32_t>(reg.size())),
+          file_name_(reg.name()),
+          line_str_ (reg.line())
+    {}
+    explicit source_location(const detail::location& loc)
+        : line_num_(static_cast<std::uint_least32_t>(std::stoul(loc.line_num()))),
+          column_num_(static_cast<std::uint_least32_t>(loc.before() + 1)),
+          region_size_(static_cast<std::uint_least32_t>(loc.size())),
+          file_name_(loc.name()),
+          line_str_ (loc.line())
+    {}
+
+    ~source_location() = default;
+    source_location(source_location const&) = default;
+    source_location(source_location &&)     = default;
+    source_location& operator=(source_location const&) = default;
+    source_location& operator=(source_location &&)     = default;
+
+    std::uint_least32_t line()      const noexcept {return line_num_;}
+    std::uint_least32_t column()    const noexcept {return column_num_;}
+    std::uint_least32_t region()    const noexcept {return region_size_;}
+
+    std::string const&  file_name() const noexcept {return file_name_;}
+    std::string const&  line_str()  const noexcept {return line_str_;}
+
+  private:
+
+    std::uint_least32_t line_num_;
+    std::uint_least32_t column_num_;
+    std::uint_least32_t region_size_;
+    std::string         file_name_;
+    std::string         line_str_;
+};
+
+namespace detail
+{
+
+// internal error message generation.
+inline std::string format_underline(const std::string& message,
+        const std::vector<std::pair<source_location, std::string>>& loc_com,
+        const std::vector<std::string>& helps = {},
+        const bool colorize = TOML11_ERROR_MESSAGE_COLORIZED)
+{
+    std::size_t line_num_width = 0;
+    for(const auto& lc : loc_com)
+    {
+        std::uint_least32_t line = lc.first.line();
+        std::size_t        digit = 0;
+        while(line != 0)
+        {
+            line  /= 10;
+            digit +=  1;
+        }
+        line_num_width = (std::max)(line_num_width, digit);
+    }
+    // 1 is the minimum width
+    line_num_width = std::max<std::size_t>(line_num_width, 1);
+
+    std::ostringstream retval;
+
+    if(colorize)
+    {
+        retval << color::colorize; // turn on ANSI color
+    }
+
+    // XXX
+    // Here, before `colorize` support, it does not output `[error]` prefix
+    // automatically. So some user may output it manually and this change may
+    // duplicate the prefix. To avoid it, check the first 7 characters and
+    // if it is "[error]", it removes that part from the message shown.
+    if(message.size() > 7 && message.substr(0, 7) == "[error]")
+    {
+        retval << color::bold << color::red << "[error]" << color::reset
+               << color::bold << message.substr(7) << color::reset << '\n';
+    }
+    else
+    {
+        retval << color::bold << color::red << "[error] " << color::reset
+               << color::bold << message << color::reset << '\n';
+    }
+
+    const auto format_one_location = [line_num_width]
+        (std::ostringstream& oss,
+         const source_location& loc, const std::string& comment) -> void
+        {
+            oss << ' ' << color::bold << color::blue
+                << std::setw(static_cast<int>(line_num_width))
+                << std::right << loc.line() << " | "  << color::reset
+                << loc.line_str() << '\n';
+
+            oss << make_string(line_num_width + 1, ' ')
+                << color::bold << color::blue << " | " << color::reset
+                << make_string(loc.column()-1 /*1-origin*/, ' ');
+
+            if(loc.region() == 1)
+            {
+                // invalid
+                // ^------
+                oss << color::bold << color::red << "^---" << color::reset;
+            }
+            else
+            {
+                // invalid
+                // ~~~~~~~
+                const auto underline_len = (std::min)(
+                    static_cast<std::size_t>(loc.region()), loc.line_str().size());
+                oss << color::bold << color::red
+                    << make_string(underline_len, '~') << color::reset;
+            }
+            oss << ' ';
+            oss << comment;
+            return;
+        };
+
+    assert(!loc_com.empty());
+
+    // --> example.toml
+    //   |
+    retval << color::bold << color::blue << " --> " << color::reset
+           << loc_com.front().first.file_name() << '\n';
+    retval << make_string(line_num_width + 1, ' ')
+           << color::bold << color::blue << " |\n"  << color::reset;
+    // 1 | key value
+    //   |    ^--- missing =
+    format_one_location(retval, loc_com.front().first, loc_com.front().second);
+
+    // process the rest of the locations
+    for(std::size_t i=1; i<loc_com.size(); ++i)
+    {
+        const auto& prev = loc_com.at(i-1);
+        const auto& curr = loc_com.at(i);
+
+        retval << '\n';
+        // if the filenames are the same, print "..."
+        if(prev.first.file_name() == curr.first.file_name())
+        {
+            retval << color::bold << color::blue << " ...\n" << color::reset;
+        }
+        else // if filename differs, print " --> filename.toml" again
+        {
+            retval << color::bold << color::blue << " --> " << color::reset
+                   << curr.first.file_name() << '\n';
+            retval << make_string(line_num_width + 1, ' ')
+                   << color::bold << color::blue << " |\n"  << color::reset;
+        }
+
+        format_one_location(retval, curr.first, curr.second);
+    }
+
+    if(!helps.empty())
+    {
+        retval << '\n';
+        retval << make_string(line_num_width + 1, ' ');
+        retval << color::bold << color::blue << " |" << color::reset;
+        for(const auto& help : helps)
+        {
+            retval << color::bold << "\nHint: " << color::reset;
+            retval << help;
+        }
+    }
+    return retval.str();
+}
+
+} // detail
+} // toml
+#endif// TOML11_SOURCE_LOCATION_HPP

toml/storage.hpp

@@ -16,10 +16,9 @@ struct storage
 {
     using value_type = T;
 
-    storage(value_type const& v): ptr(toml::make_unique<T>(v)) {}
-    storage(value_type&&      v): ptr(toml::make_unique<T>(std::move(v))) {}
+    explicit storage(value_type const& v): ptr(toml::make_unique<T>(v)) {}
+    explicit storage(value_type&&      v): ptr(toml::make_unique<T>(std::move(v))) {}
     ~storage() = default;
-
     storage(const storage& rhs): ptr(toml::make_unique<T>(*rhs.ptr)) {}
     storage& operator=(const storage& rhs)
     {

toml/string.hpp

@@ -2,8 +2,11 @@
 // Distributed under the MIT License.
 #ifndef TOML11_STRING_HPP
 #define TOML11_STRING_HPP
-#include <string>
 #include <cstdint>
+
+#include <algorithm>
+#include <string>
+
 #if __cplusplus >= 201703L
 #if __has_include(<string_view>)
 #include <string_view>
@@ -45,6 +48,11 @@ struct string
     operator std::string const& () const& noexcept {return str;}
     operator std::string&&      () &&     noexcept {return std::move(str);}
 
+    string& operator+=(const char*        rhs) {str += rhs; return *this;}
+    string& operator+=(const char         rhs) {str += rhs; return *this;}
+    string& operator+=(const std::string& rhs) {str += rhs; return *this;}
+    string& operator+=(const string&      rhs) {str += rhs.str; return *this;}
+
 #if __cplusplus >= 201703L
     explicit string(std::string_view s): kind(string_t::basic), str(s){}
     string(std::string_view s, string_t k): kind(k), str(s){}
@@ -54,6 +62,8 @@ struct string
 
     explicit operator std::string_view() const noexcept
     {return std::string_view(str);}
+
+    string& operator+=(const std::string_view& rhs) {str += rhs; return *this;}
 #endif
 
     string_t    kind;
@@ -139,9 +149,74 @@ operator>=(const char* lhs, const string& rhs) {return std::string(lhs) >= rhs.s
 
 template<typename charT, typename traits>
 std::basic_ostream<charT, traits>&
-operator<<(std::basic_ostream<charT, traits>& os, const string& str)
+operator<<(std::basic_ostream<charT, traits>& os, const string& s)
 {
-    os << str.str;
+    if(s.kind == string_t::basic)
+    {
+        if(std::find(s.str.cbegin(), s.str.cend(), '\n') != s.str.cend())
+        {
+            // it contains newline. make it multiline string.
+            os << "\"\"\"\n";
+            for(auto i=s.str.cbegin(), e=s.str.cend(); i!=e; ++i)
+            {
+                switch(*i)
+                {
+                    case '\\': {os << "\\\\"; break;}
+                    case '\"': {os << "\\\""; break;}
+                    case '\b': {os << "\\b";  break;}
+                    case '\t': {os << "\\t";  break;}
+                    case '\f': {os << "\\f";  break;}
+                    case '\n': {os << '\n';   break;}
+                    case '\r':
+                    {
+                        // since it is a multiline string,
+                        // CRLF is not needed to be escaped.
+                        if(std::next(i) != e && *std::next(i) == '\n')
+                        {
+                            os << "\r\n";
+                            ++i;
+                        }
+                        else
+                        {
+                            os << "\\r";
+                        }
+                        break;
+                    }
+                    default: {os << *i; break;}
+                }
+            }
+            os << "\\\n\"\"\"";
+            return os;
+        }
+        // no newline. make it inline.
+        os << "\"";
+        for(const auto c : s.str)
+        {
+            switch(c)
+            {
+                case '\\': {os << "\\\\"; break;}
+                case '\"': {os << "\\\""; break;}
+                case '\b': {os << "\\b";  break;}
+                case '\t': {os << "\\t";  break;}
+                case '\f': {os << "\\f";  break;}
+                case '\n': {os << "\\n";  break;}
+                case '\r': {os << "\\r";  break;}
+                default  : {os << c;      break;}
+            }
+        }
+        os << "\"";
+        return os;
+    }
+    // the string `s` is literal-string.
+    if(std::find(s.str.cbegin(), s.str.cend(), '\n') != s.str.cend() ||
+       std::find(s.str.cbegin(), s.str.cend(), '\'') != s.str.cend() )
+    {
+        // contains newline or single quote. make it multiline.
+        os << "'''\n" << s.str << "'''";
+        return os;
+    }
+    // normal literal string
+    os << '\'' << s.str << '\'';
     return os;
 }
 

toml/traits.hpp

@@ -2,11 +2,13 @@
 // Distributed under the MIT License.
 #ifndef TOML11_TRAITS_HPP
 #define TOML11_TRAITS_HPP
+#include <chrono>
+#include <forward_list>
+#include <string>
+#include <tuple>
 #include <type_traits>
 #include <utility>
-#include <chrono>
-#include <tuple>
-#include <string>
+
 #if __cplusplus >= 201703L
 #if __has_include(<string_view>)
 #include <string_view>
@@ -15,15 +17,11 @@
 
 namespace toml
 {
-
-class value; // forward decl
+template<typename C, template<typename ...> class T, template<typename ...> class A>
+class basic_value;
 
 namespace detail
 {
-
-template<typename T>
-using unwrap_t = typename std::decay<T>::type;
-
 // ---------------------------------------------------------------------------
 // check whether type T is a kind of container/map class
 
@@ -47,19 +45,35 @@ struct has_mapped_type_impl
     template<typename T> static std::true_type  check(typename T::mapped_type*);
     template<typename T> static std::false_type check(...);
 };
-struct has_resize_method_impl
+struct has_reserve_method_impl
 {
-    constexpr static std::size_t dummy=0;
-    template<typename T> static std::true_type  check(decltype(std::declval<T>().resize(dummy))*);
     template<typename T> static std::false_type check(...);
+    template<typename T> static std::true_type  check(
+        decltype(std::declval<T>().reserve(std::declval<std::size_t>()))*);
+};
+struct has_push_back_method_impl
+{
+    template<typename T> static std::false_type check(...);
+    template<typename T> static std::true_type  check(
+        decltype(std::declval<T>().push_back(std::declval<typename T::value_type>()))*);
+};
+struct is_comparable_impl
+{
+    template<typename T> static std::false_type check(...);
+    template<typename T> static std::true_type  check(
+        decltype(std::declval<T>() < std::declval<T>())*);
 };
 
 struct has_from_toml_method_impl
 {
-    template<typename T>
+    template<typename T, typename C,
+             template<typename ...> class Tb, template<typename ...> class A>
     static std::true_type  check(
-        decltype(std::declval<T>().from_toml(std::declval<::toml::value>()))*);
-    template<typename T>
+        decltype(std::declval<T>().from_toml(
+                std::declval<::toml::basic_value<C, Tb, A>>()))*);
+
+    template<typename T, typename C,
+             template<typename ...> class Tb, template<typename ...> class A>
     static std::false_type check(...);
 };
 struct has_into_toml_method_impl
@@ -85,22 +99,36 @@ struct has_key_type    : decltype(has_key_type_impl::check<T>(nullptr)){};
 template<typename T>
 struct has_mapped_type : decltype(has_mapped_type_impl::check<T>(nullptr)){};
 template<typename T>
-struct has_resize_method : decltype(has_resize_method_impl::check<T>(nullptr)){};
-
+struct has_reserve_method : decltype(has_reserve_method_impl::check<T>(nullptr)){};
 template<typename T>
+struct has_push_back_method : decltype(has_push_back_method_impl::check<T>(nullptr)){};
+template<typename T>
+struct is_comparable : decltype(is_comparable_impl::check<T>(nullptr)){};
+
+template<typename T, typename C,
+         template<typename ...> class Tb, template<typename ...> class A>
 struct has_from_toml_method
-: decltype(has_from_toml_method_impl::check<T>(nullptr)){};
+: decltype(has_from_toml_method_impl::check<T, C, Tb, A>(nullptr)){};
+
 template<typename T>
 struct has_into_toml_method
 : decltype(has_into_toml_method_impl::check<T>(nullptr)){};
 
 #ifdef __INTEL_COMPILER
-#undef decltype(...)
+#undef decltype
 #endif
 
 // ---------------------------------------------------------------------------
 // C++17 and/or/not
 
+#if __cplusplus >= 201703L
+
+using std::conjunction;
+using std::disjunction;
+using std::negation;
+
+#else
+
 template<typename ...> struct conjunction : std::true_type{};
 template<typename T>   struct conjunction<T> : T{};
 template<typename T, typename ... Ts>
@@ -118,6 +146,8 @@ struct disjunction<T, Ts...> :
 template<typename T>
 struct negation : std::integral_constant<bool, !static_cast<bool>(T::value)>{};
 
+#endif
+
 // ---------------------------------------------------------------------------
 // type checkers
 
@@ -129,6 +159,10 @@ template<typename T> struct is_std_tuple : std::false_type{};
 template<typename ... Ts>
 struct is_std_tuple<std::tuple<Ts...>> : std::true_type{};
 
+template<typename T> struct is_std_forward_list : std::false_type{};
+template<typename T>
+struct is_std_forward_list<std::forward_list<T>> : std::true_type{};
+
 template<typename T> struct is_chrono_duration: std::false_type{};
 template<typename Rep, typename Period>
 struct is_chrono_duration<std::chrono::duration<Rep, Period>>: std::true_type{};
@@ -160,9 +194,25 @@ template<typename T> struct is_container<T const&>          : is_container<T>{};
 template<typename T> struct is_container<T volatile&>       : is_container<T>{};
 template<typename T> struct is_container<T const volatile&> : is_container<T>{};
 
+template<typename T>
+struct is_basic_value: std::false_type{};
+template<typename T> struct is_basic_value<T&>                : is_basic_value<T>{};
+template<typename T> struct is_basic_value<T const&>          : is_basic_value<T>{};
+template<typename T> struct is_basic_value<T volatile&>       : is_basic_value<T>{};
+template<typename T> struct is_basic_value<T const volatile&> : is_basic_value<T>{};
+template<typename C, template<typename ...> class M, template<typename ...> class V>
+struct is_basic_value<::toml::basic_value<C, M, V>>: std::true_type{};
+
 // ---------------------------------------------------------------------------
 // C++14 index_sequence
 
+#if __cplusplus >= 201402L
+
+using std::index_sequence;
+using std::make_index_sequence;
+
+#else
+
 template<std::size_t ... Ns> struct index_sequence{};
 
 template<typename IS, std::size_t N> struct push_back_index_sequence{};
@@ -186,6 +236,22 @@ struct index_sequence_maker<0>
 template<std::size_t N>
 using make_index_sequence = typename index_sequence_maker<N-1>::type;
 
+#endif // __cplusplus >= 2014
+
+// ---------------------------------------------------------------------------
+// C++14 enable_if_t
+
+#if __cplusplus >= 201402L
+
+using std::enable_if_t;
+
+#else
+
+template<bool B, typename T>
+using enable_if_t = typename std::enable_if<B, T>::type;
+
+#endif // __cplusplus >= 2014
+
 // ---------------------------------------------------------------------------
 // return_type_of_t
 
@@ -216,6 +282,19 @@ disjunction<
         >
     >{};
 
+// ---------------------------------------------------------------------------
+// C++20 remove_cvref_t
+
+template<typename T>
+struct remove_cvref
+{
+    using type = typename std::remove_cv<
+        typename std::remove_reference<T>::type>::type;
+};
+
+template<typename T>
+using remove_cvref_t = typename remove_cvref<T>::type;
+
 }// detail
 }//toml
 #endif // TOML_TRAITS

toml/types.hpp

@@ -2,53 +2,55 @@
 // Distributed under the MIT License.
 #ifndef TOML11_TYPES_HPP
 #define TOML11_TYPES_HPP
+#include <unordered_map>
+#include <vector>
+
+#include "comments.hpp"
 #include "datetime.hpp"
 #include "string.hpp"
 #include "traits.hpp"
-#include <vector>
-#include <unordered_map>
 
 namespace toml
 {
 
-using character = char;
+template<typename Comment, // discard/preserve_comment
+         template<typename ...> class Table, // map-like class
+         template<typename ...> class Array> // vector-like class
+class basic_value;
 
-class value;
+using character = char;
 using key = std::string;
 
-using Boolean        = bool;
-using Integer        = std::int64_t;
-using Float          = double;
-using String         = ::toml::string;
-using Datetime       = offset_datetime;
-using OffsetDatetime = offset_datetime;
-using LocalDatetime  = local_datetime;
-using LocalDate      = local_date;
-using LocalTime      = local_time;
-using Array          = std::vector<value>;
-using Table          = std::unordered_map<key, value>;
+using boolean        = bool;
+using integer        = std::int64_t;
+using floating       = double; // "float" is a keyward, cannot use it here.
+// the following stuffs are structs defined here, so aliases are not needed.
+// - string
+// - offset_datetime
+// - offset_datetime
+// - local_datetime
+// - local_date
+// - local_time
 
-// alias for snake_case, consistency with STL/Boost, toml::key, toml::value
-using boolean  = Boolean;
-using integer  = Integer;
-using floating = Float;   // XXX `float` is keyword. we can't use it here
-using array    = Array;
-using table    = Table;
+// default toml::value and default array/table. these are defined after defining
+// basic_value itself.
+// using value = basic_value<discard_comments, std::unordered_map, std::vector>;
+// using array = typename value::array_type;
+// using table = typename value::table_type;
 
 enum class value_t : std::uint8_t
 {
-    Empty          = 0,
-    Boolean        = 1,
-    Integer        = 2,
-    Float          = 3,
-    String         = 4,
-    OffsetDatetime = 5,
-    LocalDatetime  = 6,
-    LocalDate      = 7,
-    LocalTime      = 8,
-    Array          = 9,
-    Table          = 10,
-    Unknown        = 255,
+    empty           =  0,
+    boolean         =  1,
+    integer         =  2,
+    floating        =  3,
+    string          =  4,
+    offset_datetime =  5,
+    local_datetime  =  6,
+    local_date      =  7,
+    local_time      =  8,
+    array           =  9,
+    table           = 10,
 };
 
 template<typename charT, typename traits>
@@ -57,27 +59,27 @@ operator<<(std::basic_ostream<charT, traits>& os, value_t t)
 {
     switch(t)
     {
-        case toml::value_t::Boolean       : os << "boolean";         return os;
-        case toml::value_t::Integer       : os << "integer";         return os;
-        case toml::value_t::Float         : os << "float";           return os;
-        case toml::value_t::String        : os << "string";          return os;
-        case toml::value_t::OffsetDatetime: os << "offset_datetime"; return os;
-        case toml::value_t::LocalDatetime : os << "local_datetime";  return os;
-        case toml::value_t::LocalDate     : os << "local_date";      return os;
-        case toml::value_t::LocalTime     : os << "local_time";      return os;
-        case toml::value_t::Array         : os << "array";           return os;
-        case toml::value_t::Table         : os << "table";           return os;
-        case toml::value_t::Empty         : os << "empty";           return os;
-        case toml::value_t::Unknown       : os << "unknown";         return os;
-        default                           : os << "nothing";         return os;
+        case value_t::boolean         : os << "boolean";         return os;
+        case value_t::integer         : os << "integer";         return os;
+        case value_t::floating        : os << "floating";        return os;
+        case value_t::string          : os << "string";          return os;
+        case value_t::offset_datetime : os << "offset_datetime"; return os;
+        case value_t::local_datetime  : os << "local_datetime";  return os;
+        case value_t::local_date      : os << "local_date";      return os;
+        case value_t::local_time      : os << "local_time";      return os;
+        case value_t::array           : os << "array";           return os;
+        case value_t::table           : os << "table";           return os;
+        case value_t::empty           : os << "empty";           return os;
+        default                       : os << "unknown";         return os;
     }
 }
 
-template<typename charT = character, typename traits = std::char_traits<charT>,
+template<typename charT = char,
+         typename traits = std::char_traits<charT>,
          typename alloc = std::allocator<charT>>
 inline std::basic_string<charT, traits, alloc> stringize(value_t t)
 {
-    std::ostringstream oss;
+    std::basic_ostringstream<charT, traits, alloc> oss;
     oss << t;
     return oss.str();
 }
@@ -85,60 +87,47 @@ inline std::basic_string<charT, traits, alloc> stringize(value_t t)
 namespace detail
 {
 
-template<typename T>
-constexpr inline value_t check_type()
-{
-    using type = typename std::remove_cv<
-                 typename std::remove_reference<T>::type
-                 >::type;
-    return std::is_same<type, toml::boolean>::value                         ? value_t::Boolean        :
-           std::is_integral<type>::value                                    ? value_t::Integer        :
-           std::is_floating_point<type>::value                              ? value_t::Float          :
-           std::is_same<type, std::string>::value                           ? value_t::String         :
-           std::is_same<type, toml::string>::value                          ? value_t::String         :
-           std::is_same<type, toml::local_date>::value                      ? value_t::LocalDate      :
-           std::is_same<type, toml::local_time>::value                      ? value_t::LocalTime      :
-           is_chrono_duration<type>::value                                  ? value_t::LocalTime      :
-           std::is_same<type, toml::local_datetime>::value                  ? value_t::LocalDatetime  :
-           std::is_same<type, toml::offset_datetime>::value                 ? value_t::OffsetDatetime :
-           std::is_same<type, std::chrono::system_clock::time_point>::value ? value_t::OffsetDatetime :
-           std::is_convertible<type, toml::array>::value                    ? value_t::Array          :
-           std::is_convertible<type, toml::table>::value                    ? value_t::Table          :
-           value_t::Unknown;
-}
+// helper to define a type that represents a value_t value.
+template<value_t V>
+using value_t_constant = std::integral_constant<value_t, V>;
 
-constexpr inline bool is_valid(value_t vt)
-{
-    return vt != value_t::Unknown;
-}
+// meta-function that convertes from value_t to the exact toml type that corresponds to.
+// It takes toml::basic_value type because array and table types depend on it.
+template<value_t t, typename Value> struct enum_to_type                      {using type = void                      ;};
+template<typename Value> struct enum_to_type<value_t::empty          , Value>{using type = void                      ;};
+template<typename Value> struct enum_to_type<value_t::boolean        , Value>{using type = boolean                   ;};
+template<typename Value> struct enum_to_type<value_t::integer        , Value>{using type = integer                   ;};
+template<typename Value> struct enum_to_type<value_t::floating       , Value>{using type = floating                  ;};
+template<typename Value> struct enum_to_type<value_t::string         , Value>{using type = string                    ;};
+template<typename Value> struct enum_to_type<value_t::offset_datetime, Value>{using type = offset_datetime           ;};
+template<typename Value> struct enum_to_type<value_t::local_datetime , Value>{using type = local_datetime            ;};
+template<typename Value> struct enum_to_type<value_t::local_date     , Value>{using type = local_date                ;};
+template<typename Value> struct enum_to_type<value_t::local_time     , Value>{using type = local_time                ;};
+template<typename Value> struct enum_to_type<value_t::array          , Value>{using type = typename Value::array_type;};
+template<typename Value> struct enum_to_type<value_t::table          , Value>{using type = typename Value::table_type;};
 
-template<value_t t> struct toml_default_type;
-template<> struct toml_default_type<value_t::Boolean >      {typedef boolean         type;};
-template<> struct toml_default_type<value_t::Integer >      {typedef integer         type;};
-template<> struct toml_default_type<value_t::Float   >      {typedef floating        type;};
-template<> struct toml_default_type<value_t::String  >      {typedef string          type;};
-template<> struct toml_default_type<value_t::OffsetDatetime>{typedef offset_datetime type;};
-template<> struct toml_default_type<value_t::LocalDatetime> {typedef local_datetime  type;};
-template<> struct toml_default_type<value_t::LocalDate>     {typedef local_date      type;};
-template<> struct toml_default_type<value_t::LocalTime>     {typedef local_time      type;};
-template<> struct toml_default_type<value_t::Array   >      {typedef array           type;};
-template<> struct toml_default_type<value_t::Table   >      {typedef table           type;};
-template<> struct toml_default_type<value_t::Empty   >      {typedef void            type;};
-template<> struct toml_default_type<value_t::Unknown >      {typedef void            type;};
+// meta-function that converts from an exact toml type to the enum that corresponds to.
+template<typename T, typename Value>
+struct type_to_enum : std::conditional<
+    std::is_same<T, typename Value::array_type>::value, // if T == array_type,
+    value_t_constant<value_t::array>,                   // then value_t::array
+    typename std::conditional<                          // else...
+        std::is_same<T, typename Value::table_type>::value, // if T == table_type
+        value_t_constant<value_t::table>,               // then value_t::table
+        value_t_constant<value_t::empty>                // else value_t::empty
+        >::type
+    >::type {};
+template<typename Value> struct type_to_enum<boolean        , Value>: value_t_constant<value_t::boolean        > {};
+template<typename Value> struct type_to_enum<integer        , Value>: value_t_constant<value_t::integer        > {};
+template<typename Value> struct type_to_enum<floating       , Value>: value_t_constant<value_t::floating       > {};
+template<typename Value> struct type_to_enum<string         , Value>: value_t_constant<value_t::string         > {};
+template<typename Value> struct type_to_enum<offset_datetime, Value>: value_t_constant<value_t::offset_datetime> {};
+template<typename Value> struct type_to_enum<local_datetime , Value>: value_t_constant<value_t::local_datetime > {};
+template<typename Value> struct type_to_enum<local_date     , Value>: value_t_constant<value_t::local_date     > {};
+template<typename Value> struct type_to_enum<local_time     , Value>: value_t_constant<value_t::local_time     > {};
 
-template<typename T> struct toml_value_t       {static constexpr value_t value = value_t::Unknown       ;};
-template<> struct toml_value_t<boolean        >{static constexpr value_t value = value_t::Boolean       ;};
-template<> struct toml_value_t<integer        >{static constexpr value_t value = value_t::Integer       ;};
-template<> struct toml_value_t<floating       >{static constexpr value_t value = value_t::Float         ;};
-template<> struct toml_value_t<string         >{static constexpr value_t value = value_t::String        ;};
-template<> struct toml_value_t<offset_datetime>{static constexpr value_t value = value_t::OffsetDatetime;};
-template<> struct toml_value_t<local_datetime >{static constexpr value_t value = value_t::LocalDatetime ;};
-template<> struct toml_value_t<local_date     >{static constexpr value_t value = value_t::LocalDate     ;};
-template<> struct toml_value_t<local_time     >{static constexpr value_t value = value_t::LocalTime     ;};
-template<> struct toml_value_t<array          >{static constexpr value_t value = value_t::Array         ;};
-template<> struct toml_value_t<table          >{static constexpr value_t value = value_t::Table         ;};
-
-template<typename T>
+// meta-function that checks the type T is the same as one of the toml::* types.
+template<typename T, typename Value>
 struct is_exact_toml_type : disjunction<
     std::is_same<T, boolean        >,
     std::is_same<T, integer        >,
@@ -148,13 +137,13 @@ struct is_exact_toml_type : disjunction<
     std::is_same<T, local_datetime >,
     std::is_same<T, local_date     >,
     std::is_same<T, local_time     >,
-    std::is_same<T, array          >,
-    std::is_same<T, table          >
+    std::is_same<T, typename Value::array_type>,
+    std::is_same<T, typename Value::table_type>
     >{};
-template<typename T> struct is_exact_toml_type<T&>               : is_exact_toml_type<T>{};
-template<typename T> struct is_exact_toml_type<T const&>         : is_exact_toml_type<T>{};
-template<typename T> struct is_exact_toml_type<T volatile&>      : is_exact_toml_type<T>{};
-template<typename T> struct is_exact_toml_type<T const volatile&>: is_exact_toml_type<T>{};
+template<typename T, typename V> struct is_exact_toml_type<T&, V>               : is_exact_toml_type<T, V>{};
+template<typename T, typename V> struct is_exact_toml_type<T const&, V>         : is_exact_toml_type<T, V>{};
+template<typename T, typename V> struct is_exact_toml_type<T volatile&, V>      : is_exact_toml_type<T, V>{};
+template<typename T, typename V> struct is_exact_toml_type<T const volatile&, V>: is_exact_toml_type<T, V>{};
 
 } // detail
 } // toml

toml/utility.hpp

@@ -2,10 +2,11 @@
 // Distributed under the MIT License.
 #ifndef TOML11_UTILITY_HPP
 #define TOML11_UTILITY_HPP
-#include "traits.hpp"
-#include <utility>
 #include <memory>
 #include <sstream>
+#include <utility>
+
+#include "traits.hpp"
 
 #if __cplusplus >= 201402L
 #  define TOML11_MARK_AS_DEPRECATED(msg) [[deprecated(msg)]]
@@ -20,38 +21,41 @@
 namespace toml
 {
 
+#if __cplusplus >= 201402L
+
+using std::make_unique;
+
+#else
+
 template<typename T, typename ... Ts>
 inline std::unique_ptr<T> make_unique(Ts&& ... args)
 {
     return std::unique_ptr<T>(new T(std::forward<Ts>(args)...));
 }
 
+#endif // __cplusplus >= 2014
+
 namespace detail
 {
-
-template<typename T>
-inline void resize_impl(T& container, std::size_t N, std::true_type)
+template<typename Container>
+void try_reserve_impl(Container& container, std::size_t N, std::true_type)
 {
-    container.resize(N);
-    return ;
+    container.reserve(N);
+    return;
 }
-
-template<typename T>
-inline void resize_impl(T& container, std::size_t N, std::false_type)
+template<typename Container>
+void try_reserve_impl(Container&, std::size_t, std::false_type) noexcept
 {
-    if(container.size() >= N) {return;}
-
-    throw std::invalid_argument("not resizable type");
+    return;
 }
-
 } // detail
 
-template<typename T>
-inline void resize(T& container, std::size_t N)
+template<typename Container>
+void try_reserve(Container& container, std::size_t N)
 {
-    if(container.size() == N) {return;}
-
-    return detail::resize_impl(container, N, detail::has_resize_method<T>());
+    if(N <= container.size()) {return;}
+    detail::try_reserve_impl(container, N, detail::has_reserve_method<Container>{});
+    return;
 }
 
 namespace detail
@@ -76,10 +80,10 @@ std::string concat_to_string(Ts&& ... args)
     return detail::concat_to_string_impl(oss, std::forward<Ts>(args) ...);
 }
 
-template<typename T, typename U>
-T from_string(const std::string& str, U&& opt)
+template<typename T>
+T from_string(const std::string& str, T opt)
 {
-    T v(static_cast<T>(std::forward<U>(opt)));
+    T v(opt);
     std::istringstream iss(str);
     iss >> v;
     return v;