chore: update README badges

fix: open file as binary-mode #16

README.md

@@ -3,10 +3,11 @@ toml11
 
 [![Build Status](https://travis-ci.org/ToruNiina/toml11.svg?branch=master)](https://travis-ci.org/ToruNiina/toml11)
 [![Build status](https://ci.appveyor.com/api/projects/status/m2n08a926asvg5mg?svg=true)](https://ci.appveyor.com/project/ToruNiina/toml11)
-[![MIT License](http://img.shields.io/badge/license-MIT-blue.svg?style=flat)](LICENSE)
+[![Version](https://img.shields.io/github/release/ToruNiina/toml11.svg?style=flat)](https://github.com/ToruNiina/toml11/releases)
+[![License](https://img.shields.io/github/license/ToruNiina/toml11.svg?style=flat)](LICENSE)
 [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.1209136.svg)](https://doi.org/10.5281/zenodo.1209136)
 
-c++11 header-only toml parser depending only on c++ standard library.
+C++11 header-only toml parser depending only on C++ standard library.
 
 compatible to the latest version of [TOML v0.5.0](https://github.com/toml-lang/toml/blob/master/versions/en/toml-v0.5.0.md) after version 2.0.0.
 
@@ -42,8 +43,14 @@ In the case of file open error, it will throw `std::runtime_error`.
 
 You can also pass a `stream` to the  `toml::parse` function after checking the status.
 
+Note that on __Windows OS__, stream that is opened as text-mode automatically converts
+CRLF ("\r\n") into LF ("\n") and this leads inconsistency between file size and
+the contents that would be read. This causes weird error. To use a file stream
+with `toml::parse`, don't forget to pass binary mode flag when you open the
+stream.
+
 ```cpp
-std::ifstream ifs("sample.toml");
+std::ifstream ifs("sample.toml", std::ios_base::binary);
 assert(ifs.good());
 const auto data = toml::parse(ifs /*, "filename" (optional)*/);
 ```
@@ -446,7 +453,7 @@ if(max < min)
 you will get an error message like this.
 
 ```console
-[error] value should be positive
+[error] max should be larger than min
  --> example.toml
  3 | min = 54
    |       ~~ minimum number here
@@ -485,6 +492,8 @@ I thank the contributor for providing great feature to this repository.
 - Guillaume Fraux (@Luthaf)
   - Windows support and CI on Appvayor
   - Intel Compiler support
+- Quentin Khan (@xaxousis)
+  - Found & Fixed a bug around ODR
 
 ## Licensing terms
 

tests/CMakeLists.txt

@@ -26,6 +26,7 @@ set(TEST_NAMES
     test_from_toml
     test_parse_file
     test_parse_unicode
+    test_error_detection
 )
 
 CHECK_CXX_COMPILER_FLAG("-Wall" COMPILER_SUPPORTS_WALL)

tests/test_error_detection.cpp

@@ -0,0 +1,199 @@
+#define BOOST_TEST_MODULE "test_error_detection"
+#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 <iostream>
+#include <fstream>
+
+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_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_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_AUTO_TEST_CASE(test_detect_duplicate_table)
+{
+    std::istringstream stream(std::string(
+            "[table]\n"
+            "a = 42\n"
+            "[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_AUTO_TEST_CASE(test_detect_conflict_array_table)
+{
+    std::istringstream stream(std::string(
+            "[[table]]\n"
+            "a = 42\n"
+            "[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_AUTO_TEST_CASE(test_detect_conflict_table_array)
+{
+    std::istringstream stream(std::string(
+            "[table]\n"
+            "a = 42\n"
+            "[[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_AUTO_TEST_CASE(test_detect_duplicate_value)
+{
+    std::istringstream stream(std::string(
+            "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_AUTO_TEST_CASE(test_detect_conflicting_value)
+{
+    std::istringstream stream(std::string(
+            "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_AUTO_TEST_CASE(test_detect_inhomogeneous_array)
+{
+    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_AUTO_TEST_CASE(test_detect_appending_array_of_table)
+{
+    std::istringstream stream(std::string(
+            "a = [{b = 1}]\n"
+            "[[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);
+}
+

tests/test_get_related_func.cpp

@@ -68,9 +68,14 @@ BOOST_AUTO_TEST_CASE(test_expect)
     {
         toml::value v1(42);
         toml::value v2(3.14);
-        BOOST_CHECK_EQUAL(42, toml::expect<int>(v1).unwrap_or(0));
+        const auto v1_or_0 = toml::expect<int>(v1).unwrap_or(0);
-        BOOST_CHECK_EQUAL( 0, toml::expect<int>(v2).unwrap_or(0));
+        const auto v2_or_0 = toml::expect<int>(v2).unwrap_or(0);
-        BOOST_CHECK_EQUAL("42",   toml::expect<int>(v1).map([](int i){return std::to_string(i);}).unwrap_or(std::string("none")));
+        BOOST_CHECK_EQUAL(42, v1_or_0);
-        BOOST_CHECK_EQUAL("none", toml::expect<int>(v2).map([](int i){return std::to_string(i);}).unwrap_or(std::string("none")));
+        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_parse_file.cpp

@@ -194,3 +194,504 @@ BOOST_AUTO_TEST_CASE(test_hard_example)
     BOOST_CHECK(toml::get<std::vector<std::string>>(bit.at("multi_line_array")) ==
                 expected_multi_line_array);
 }
+
+// ---------------------------------------------------------------------------
+// after here, the test codes generate the content of a file.
+
+BOOST_AUTO_TEST_CASE(test_file_with_BOM)
+{
+    {
+        const std::string table(
+            "\xEF\xBB\xBF" // BOM
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            );
+        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");
+    }
+    {
+        const std::string table(
+            "\xEF\xBB\xBF" // BOM
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            );
+        {
+            std::ofstream ofs("tmp.toml");
+            ofs << table;
+        }
+        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");
+    }
+    {
+        const std::string table(
+            "\xEF\xBB\xBF" // BOM
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            );
+        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");
+    }
+    {
+        const std::string table(
+            "\xEF\xBB\xBF" // BOM
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            );
+        {
+            // with text-mode, "\n" is converted to "\r\n" and the resulting
+            // 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());
+        }
+        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_AUTO_TEST_CASE(test_file_without_newline_at_the_end_of_file)
+{
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\""
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\""
+            );
+        std::istringstream iss(table);
+        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");
+    }
+
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\" # comment"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\" # comment"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\" \t"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\" \t"
+            );
+        std::istringstream iss(table);
+        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_AUTO_TEST_CASE(test_files_end_with_comment)
+{
+    // comment w/o newline
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "# comment"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "# comment\n"
+            "# one more comment"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+
+    // comment w/ newline
+
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "# comment\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "# comment\n"
+            "# one more comment\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+
+    // CRLF version
+
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            "# comment"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            "# comment\r\n"
+            "# one more comment"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            "# comment\r\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            "# comment\r\n"
+            "# one more comment\r\n"
+            );
+        std::istringstream iss(table);
+        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_AUTO_TEST_CASE(test_files_end_with_empty_lines)
+{
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "\n"
+            "\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+
+    // with whitespaces
+
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "  \n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "  \n"
+            "  \n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "\n"
+            "  \n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "  \n"
+            "\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+
+    // with whitespaces but no newline
+    {
+        const std::string table(
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            "  "
+            );
+        std::istringstream iss(table);
+        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");
+    }
+
+
+    // CRLF
+
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            "\r\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            "\r\n"
+            "\r\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+
+    // with whitespaces
+
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            "  \r\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            "\r\n"
+            "  \r\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            "  \r\n"
+            "\r\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            "  \r\n"
+            "  \r\n"
+            );
+        std::istringstream iss(table);
+        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");
+    }
+    {
+        const std::string table(
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            "  "
+            );
+        std::istringstream iss(table);
+        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");
+    }
+}

tests/test_result.cpp

@@ -409,3 +409,33 @@ BOOST_AUTO_TEST_CASE(test_or_else)
         BOOST_CHECK_EQUAL(mapped.unwrap_err(), "hogehoge");
     }
 }
+
+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());
+    }
+    {
+        auto r1_gen = []() -> toml::result<int, std::string> {
+            return toml::ok(42);
+        };
+        auto r2_gen = []() -> toml::result<int, std::string> {
+            return toml::err<std::string>("foo");
+        };
+        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());
+    }
+}
+
+

toml/get.hpp

@@ -295,7 +295,7 @@ T get(const toml::value& v)
 // ============================================================================
 // find and get
 
-template<typename T>
+template<typename T = ::toml::value>
 decltype(::toml::get<T>(std::declval<const ::toml::value&>()))
 find(const toml::table& tab, const toml::key& ky,
      std::string tablename = "unknown table")
@@ -307,7 +307,7 @@ find(const toml::table& tab, const toml::key& ky,
     }
     return ::toml::get<T>(tab.at(ky));
 }
-template<typename T>
+template<typename T = ::toml::value>
 decltype(::toml::get<T>(std::declval<::toml::value&>()))
 find(toml::table& tab, const toml::key& ky,
      std::string tablename = "unknown table")
@@ -319,7 +319,7 @@ find(toml::table& tab, const toml::key& ky,
     }
     return ::toml::get<T>(tab[ky]);
 }
-template<typename T>
+template<typename T = ::toml::value>
 decltype(::toml::get<T>(std::declval<::toml::value&&>()))
 find(toml::table&& tab, const toml::key& ky,
      std::string tablename = "unknown table")
@@ -332,7 +332,7 @@ find(toml::table&& tab, const toml::key& ky,
     return ::toml::get<T>(std::move(tab[ky]));
 }
 
-template<typename T>
+template<typename T = ::toml::value>
 decltype(::toml::get<T>(std::declval<const ::toml::value&>()))
 find(const toml::value& v, const toml::key& ky)
 {
@@ -345,7 +345,7 @@ find(const toml::value& v, const toml::key& ky)
     }
     return ::toml::get<T>(tab.at(ky));
 }
-template<typename T>
+template<typename T = ::toml::value>
 decltype(::toml::get<T>(std::declval<::toml::value&>()))
 find(toml::value& v, const toml::key& ky)
 {
@@ -358,7 +358,7 @@ find(toml::value& v, const toml::key& ky)
     }
     return ::toml::get<T>(tab.at(ky));
 }
-template<typename T>
+template<typename T = ::toml::value>
 decltype(::toml::get<T>(std::declval<::toml::value&&>()))
 find(toml::value&& v, const toml::key& ky)
 {

toml/parser.hpp

@@ -34,8 +34,8 @@ parse_boolean(location<Container>& loc)
         }
     }
     loc.iter() = first; //rollback
-    return err(format_underline("[error] toml::parse_boolean", loc,
+    return err(std::string("[error] toml::parse_boolean: "
-            "token is not boolean", {"boolean is `true` or `false`"}));
+                           "the next token is not a boolean"));
 }
 
 template<typename Container>
@@ -63,8 +63,8 @@ parse_binary_integer(location<Container>& loc)
         return ok(std::make_pair(retval, token.unwrap()));
     }
     loc.iter() = first;
-    return err(format_underline("[error] toml::parse_binary_integer", loc,
+    return err(std::string("[error] toml::parse_binary_integer:"
-            "token is not binary integer", {"binary integer is like: 0b0011"}));
+                           "the next token is not an integer"));
 }
 
 template<typename Container>
@@ -84,9 +84,8 @@ parse_octal_integer(location<Container>& loc)
         return ok(std::make_pair(retval, token.unwrap()));
     }
     loc.iter() = first;
-
+    return err(std::string("[error] toml::parse_octal_integer:"
-    return err(format_underline("[error] toml::parse_octal_integer", loc,
+                           "the next token is not an integer"));
-            "token is not octal integer", {"octal integer is like: 0o775"}));
 }
 
 template<typename Container>
@@ -106,8 +105,8 @@ parse_hexadecimal_integer(location<Container>& loc)
         return ok(std::make_pair(retval, token.unwrap()));
     }
     loc.iter() = first;
-    return err(format_underline("[error] toml::parse_hexadecimal_integer", loc,
+    return err(std::string("[error] toml::parse_hexadecimal_integer"
-            "token is not hex integer", {"hex integer is like: 0xC0FFEE"}));
+                           "the next token is not an integer"));
 }
 
 template<typename Container>
@@ -134,10 +133,8 @@ parse_integer(location<Container>& loc)
         return ok(std::make_pair(retval, token.unwrap()));
     }
     loc.iter() = first;
-    return err(format_underline("[error] toml::parse_integer", loc,
+    return err(std::string("[error] toml::parse_integer: "
-            "token is not integer", {"integer is like: +42",
+                           "the next token is not an integer"));
-            "hex integer is like: 0xC0FFEE", "octal integer is like: 0o775",
-            "binary integer is like: 0b0011"}));
 }
 
 template<typename Container>
@@ -225,8 +222,8 @@ parse_floating(location<Container>& loc)
         return ok(std::make_pair(v, token.unwrap()));
     }
     loc.iter() = first;
-    return err(format_underline("[error] toml::parse_floating: ", loc,
+    return err(std::string("[error] toml::parse_floating: "
-                "token is not a float", {"floating point is like: -3.14e+1"}));
+                           "the next token is not a float"));
 }
 
 template<typename Container>
@@ -286,9 +283,8 @@ result<std::string, std::string> parse_escape_sequence(location<Container>& loc)
     const auto first = loc.iter();
     if(first == loc.end() || *first != '\\')
     {
-        return err(format_underline("[error]: "
+        return err(std::string("[error]: toml::parse_escape_sequence: "
-            "toml::parse_escape_sequence: location does not points \"\\\"",
+                    "the next token is not an escape sequence \"\\\""));
-            loc, "should be \"\\\""));
     }
     ++loc.iter();
     switch(*loc.iter())
@@ -527,8 +523,8 @@ parse_string(location<Container>& loc)
     if(const auto rslt = parse_ml_literal_string(loc)) {return rslt;}
     if(const auto rslt = parse_basic_string(loc))      {return rslt;}
     if(const auto rslt = parse_literal_string(loc))    {return rslt;}
-    return err(format_underline("[error] toml::parse_string: not a string",
+    return err(std::string("[error] toml::parse_string: "
-               loc, "not a string"));
+                "the next token is not a string"));
 }
 
 template<typename Container>
@@ -576,11 +572,9 @@ parse_local_date(location<Container>& loc)
     }
     else
     {
-        auto msg = format_underline("[error]: toml::parse_local_date: "
-                "invalid format", loc, token.unwrap_err(),
-                {"local date is like: 1979-05-27"});
         loc.iter() = first;
-        return err(std::move(msg));
+        return err(std::string("[error]: toml::parse_local_date: "
+                    "the next token is not a local_date"));
     }
 }
 
@@ -661,11 +655,9 @@ parse_local_time(location<Container>& loc)
     }
     else
     {
-        auto msg = format_underline("[error]: toml::parse_local_time: "
-                "invalid format", loc, token.unwrap_err(),
-                {"local time is like: 00:32:00.999999"});
         loc.iter() = first;
-        return err(std::move(msg));
+        return err(std::string("[error]: toml::parse_local_time: "
+                    "the next token is not a local_time"));
     }
 }
 
@@ -706,11 +698,9 @@ parse_local_datetime(location<Container>& loc)
     }
     else
     {
-        auto msg = format_underline("[error]: toml::parse_local_datetime: "
-                    "invalid format", loc, token.unwrap_err(),
-                    {"local datetime is like: 1979-05-27T00:32:00.999999"});
         loc.iter() = first;
-        return err(std::move(msg));
+        return err(std::string("[error]: toml::parse_local_datetime: "
+                    "the next token is not a local_datetime"));
     }
 }
 
@@ -757,12 +747,9 @@ parse_offset_datetime(location<Container>& loc)
     }
     else
     {
-        auto msg = format_underline("[error]: toml::parse_offset_datetime: "
-                    "invalid format", loc, token.unwrap_err(),
-                    {"offset datetime is like: 1979-05-27T00:32:00-07:00",
-                     "or in UTC (w/o offset) : 1979-05-27T00:32:00Z"});
         loc.iter() = first;
-        return err(std::move(msg));
+        return err(std::string("[error]: toml::parse_offset_datetime: "
+                    "the next token is not a local_datetime"));
     }
 }
 
@@ -781,8 +768,8 @@ result<key, std::string> parse_simple_key(location<Container>& loc)
     {
         return ok(bare.unwrap().str());
     }
-    return err(format_underline("[error] toml::parse_simple_key: "
+    return err(std::string("[error] toml::parse_simple_key: "
-        "the next token is not a simple key", loc, "not a key"));
+        "the next token is not a simple key"));
 }
 
 // dotted key become vector of keys
@@ -835,8 +822,8 @@ result<std::vector<key>, std::string> parse_key(location<Container>& loc)
     {
         return ok(std::vector<key>(1, smpl.unwrap()));
     }
-    return err(format_underline("toml::parse_key: the next token is not a key",
+    return err(std::string("[error] toml::parse_key: "
-                loc, "not a key"));
+                           "the next token is not a key"));
 }
 
 // forward-decl to implement parse_array and parse_table
@@ -854,8 +841,7 @@ parse_array(location<Container>& loc)
     }
     if(*loc.iter() != '[')
     {
-        return err(format_underline("[error] toml::parse_array: "
+        return err("[error] toml::parse_array: token is not an array");
-            "token is not an array", loc,  "should be ["));
     }
     ++loc.iter();
 
@@ -903,13 +889,13 @@ parse_array(location<Container>& loc)
             }
             else
             {
-                return err(format_underline("[error] toml::parse_array: "
+                throw syntax_error(format_underline("[error] toml::parse_array:"
                     " missing array separator `,`", loc, "should be `,`"));
             }
         }
     }
     loc.iter() = first;
-    return err(format_underline("[error] toml::parse_array: "
+    throw syntax_error(format_underline("[error] toml::parse_array: "
             "array did not closed by `]`", loc, "should be closed"));
 }
 
@@ -971,7 +957,8 @@ parse_key_value_pair(location<Container>& loc)
         }
         else
         {
-            msg = val.unwrap_err();
+            msg = format_underline("[error] toml::parse_key_value_pair: "
+                    "invalid value format", loc, val.unwrap_err());
         }
         loc.iter() = first;
         return err(msg);
@@ -1035,9 +1022,9 @@ insert_nested_key(table& root, const toml::value& v,
                             "[error] toml::insert_value: array of table (\"",
                             format_dotted_keys(first, last), "\") collides with"
                             " existing value"), get_region(tab->at(k)),
-                            concat_to_string("this ", tab->at(k).type(), "value"
+                            concat_to_string("this ", tab->at(k).type(),
-                            "already exists"), get_region(v), "while inserting"
+                            " value already exists"), get_region(v),
-                            "this array-of-tables"));
+                            "while inserting this array-of-tables"));
                     }
                     array& a = tab->at(k).template cast<toml::value_t::Array>();
                     if(!(a.front().is(value_t::Table)))
@@ -1046,9 +1033,34 @@ insert_nested_key(table& root, const toml::value& v,
                             "[error] toml::insert_value: array of table (\"",
                             format_dotted_keys(first, last), "\") collides with"
                             " existing value"), get_region(tab->at(k)),
-                            concat_to_string("this ", tab->at(k).type(), "value"
+                            concat_to_string("this ", tab->at(k).type(),
-                            "already exists"), get_region(v), "while inserting"
+                            " value already exists"), get_region(v),
-                            "this array-of-tables"));
+                            "while inserting this array-of-tables"));
+                    }
+                    // avoid conflicting array of table like the following.
+                    // ```toml
+                    // a = [{b = 42}] # define a as an array of *inline* tables
+                    // [[a]]          # a is an array of *multi-line* tables
+                    // b = 54
+                    // ```
+                    // Here, from the type information, these cannot be detected
+                    // bacause inline table is also a table.
+                    // But toml v0.5.0 explicitly says it is invalid. The above
+                    // array-of-tables has a static size and appending to the
+                    // array is invalid.
+                    // In this library, multi-line table value has a region
+                    // that points to the key of the table (e.g. [[a]]). By
+                    // comparing the first two letters in key, we can detect
+                    // the array-of-table is inline or multiline.
+                    if(detail::get_region(a.front()).str().substr(0,2) != "[[")
+                    {
+                        throw syntax_error(format_underline(concat_to_string(
+                            "[error] toml::insert_value: array of table (\"",
+                            format_dotted_keys(first, last), "\") collides with"
+                            " existing array-of-tables"), get_region(tab->at(k)),
+                            concat_to_string("this ", tab->at(k).type(),
+                            " value has static size"), get_region(v),
+                            "appending this to the statically sized array"));
                     }
                     a.push_back(v);
                     return ok(true);
@@ -1155,10 +1167,11 @@ parse_inline_table(location<Container>& loc)
     table retval;
     if(!(loc.iter() != loc.end() && *loc.iter() == '{'))
     {
-        return err(format_underline("[error] toml::parse_inline_table: "
+        return err(std::string("[error] toml::parse_inline_table: "
-            "the next token is not an inline table", loc, "not `{`."));
+                               "the next token is not an inline table"));
     }
     ++loc.iter();
+    // it starts from "{". it should be formatted as inline-table
     while(loc.iter() != loc.end())
     {
         maybe<lex_ws>::invoke(loc);
@@ -1198,13 +1211,14 @@ parse_inline_table(location<Container>& loc)
             }
             else
             {
-                return err(format_underline("[error] toml:::parse_inline_table:"
+                throw syntax_error(format_underline("[error] "
-                    " missing table separator `,` ", loc, "should be `,`"));
+                    "toml:::parse_inline_table: missing table separator `,` ",
+                    loc, "should be `,`"));
             }
         }
     }
     loc.iter() = first;
-    return err(format_underline("[error] toml::parse_inline_table: "
+    throw syntax_error(format_underline("[error] toml::parse_inline_table: "
             "inline table did not closed by `}`", loc, "should be closed"));
 }
 
@@ -1331,7 +1345,7 @@ result<table, std::string> parse_ml_table(location<Container>& loc)
         return err(std::string("toml::parse_ml_table: input is empty"));
     }
 
-    // XXX at lest one newline is needed
+    // XXX at lest one newline is needed.
     using skip_line = repeat<
         sequence<maybe<lex_ws>, maybe<lex_comment>, lex_newline>, at_least<1>>;
     skip_line::invoke(loc);
@@ -1351,6 +1365,7 @@ result<table, std::string> parse_ml_table(location<Container>& loc)
             loc.iter() = before;
             return ok(tab);
         }
+
         if(const auto kv = parse_key_value_pair(loc))
         {
             const std::vector<key>& keys = kv.unwrap().first;
@@ -1367,6 +1382,17 @@ result<table, std::string> parse_ml_table(location<Container>& loc)
             return err(kv.unwrap_err());
         }
 
+        // comment lines are skipped by the above function call.
+        // However, since the `skip_line` requires at least 1 newline, it fails
+        // if the file ends with ws and/or comment without newline.
+        // `skip_line` matches `ws? + comment? + newline`, not `ws` or `comment`
+        // itself. To skip the last ws and/or comment, call lexers.
+        // It does not matter if these fails, so the return value is discarded.
+        lex_ws::invoke(loc);
+        lex_comment::invoke(loc);
+
+        // skip_line is (whitespace? comment? newline)_{1,}. multiple empty lines
+        // and comments after the last key-value pairs are allowed.
         const auto newline = skip_line::invoke(loc);
         if(!newline && loc.iter() != loc.end())
         {
@@ -1379,11 +1405,10 @@ result<table, std::string> parse_ml_table(location<Container>& loc)
             return err(msg);
         }
 
-        // comment lines are skipped by the above function call.
+        // the skip_lines only matches with lines that includes newline.
-        // However, if the file ends with comment without newline,
+        // to skip the last line that includes comment and/or whitespace
-        // it might cause parsing error because skip_line matches
+        // but no newline, call them one more time.
-        // `comment + newline`, not `comment` itself. to skip the
+        lex_ws::invoke(loc);
-        // last comment, call lex_comment one more time.
         lex_comment::invoke(loc);
     }
     return ok(tab);
@@ -1472,10 +1497,10 @@ inline table parse(std::istream& is, std::string fname = "unknown file")
     // be compared to char. However, since we are always out of luck, we need to
     // check our chars are equivalent to BOM. To do this, first we need to
     // convert char to unsigned char to guarantee the comparability.
-    if(letters.size() >= 3)
+    if(loc.source()->size() >= 3)
     {
         std::array<unsigned char, 3> BOM;
-        std::memcpy(BOM.data(), letters.data(), 3);
+        std::memcpy(BOM.data(), loc.source()->data(), 3);
         if(BOM[0] == 0xEF && BOM[1] == 0xBB && BOM[2] == 0xBF)
         {
             loc.iter() += 3; // BOM found. skip.
@@ -1492,7 +1517,7 @@ inline table parse(std::istream& is, std::string fname = "unknown file")
 
 inline table parse(const std::string& fname)
 {
-    std::ifstream ifs(fname.c_str());
+    std::ifstream ifs(fname.c_str(), std::ios_base::binary);
     if(!ifs.good())
     {
         throw std::runtime_error("toml::parse: file open error -> " + fname);

toml/region.hpp

@@ -262,10 +262,8 @@ inline std::string format_underline(const std::string& message,
         std::max(line_number1.size(), line_number2.size());
 
     std::ostringstream retval;
-    retval << message;
+    retval << message << newline;
-    retval << newline;
+    retval << " --> " << reg1.name() << newline;
-    retval << " --> ";
-    retval << reg1.name() << newline;;
 //  ---------------------------------------
     retval << ' ' << std::setw(line_num_width) << line_number1;
     retval << " | " << line1 << newline;
@@ -276,7 +274,14 @@ inline std::string format_underline(const std::string& message,
     retval << ' ';
     retval << comment_for_underline1 << newline;
 //  ---------------------------------------
+    if(reg2.name() != reg1.name())
+    {
+        retval << " --> " << reg2.name() << newline;
+    }
+    else
+    {
         retval << " ..." << newline;
+    }
     retval << ' ' << std::setw(line_num_width) << line_number2;
     retval << " | " << line2 << newline;
     retval << make_string(line_num_width + 1, ' ');

toml/result.hpp

@@ -2,6 +2,7 @@
 // Distributed under the MIT License.
 #ifndef TOML11_RESULT_H
 #define TOML11_RESULT_H
+#include "traits.hpp"
 #include <type_traits>
 #include <stdexcept>
 #include <utility>
@@ -13,19 +14,6 @@
 namespace toml
 {
 
-#if __cplusplus >= 201703L
-
-template<typename F, typename ... Args>
-using return_type_of_t = std::invoke_result_t<F, Args...>;
-
-#else
-// result_of is deprecated after C++17
-template<typename F, typename ... Args>
-using return_type_of_t = typename std::result_of<F(Args...)>::type;
-
-#endif
-
-
 template<typename T>
 struct success
 {
@@ -396,23 +384,20 @@ struct result
         return std::move(this->succ.value);
     }
 
-    template<typename U>
+    value_type&       unwrap_or(value_type& opt) &
-    value_type&       unwrap_or(U& opt) &
     {
         if(is_err()) {return opt;}
         return this->succ.value;
     }
-    template<typename U>
+    value_type const& unwrap_or(value_type const& opt) const&
-    value_type const& unwrap_or(U const& opt) const&
     {
         if(is_err()) {return opt;}
         return this->succ.value;
     }
-    template<typename U>
+    value_type        unwrap_or(value_type opt) &&
-    value_type&&      unwrap_or(U&& opt) &&
     {
-        if(is_err()) {return std::move(opt);}
+        if(is_err()) {return opt;}
-        return std::move(this->succ.value);
+        return this->succ.value;
     }
 
     error_type&       unwrap_err() &
@@ -444,21 +429,21 @@ struct result
     // F: T -> U
     // retval: result<U, E>
     template<typename F>
-    result<return_type_of_t<F, value_type&>, error_type>
+    result<detail::return_type_of_t<F, value_type&>, error_type>
     map(F&& f) &
     {
         if(this->is_ok()){return ok(f(this->as_ok()));}
         return err(this->as_err());
     }
     template<typename F>
-    result<return_type_of_t<F, value_type const&>, error_type>
+    result<detail::return_type_of_t<F, value_type const&>, error_type>
     map(F&& f) const&
     {
         if(this->is_ok()){return ok(f(this->as_ok()));}
         return err(this->as_err());
     }
     template<typename F>
-    result<return_type_of_t<F, value_type &&>, error_type>
+    result<detail::return_type_of_t<F, value_type &&>, error_type>
     map(F&& f) &&
     {
         if(this->is_ok()){return ok(f(std::move(this->as_ok())));}
@@ -469,21 +454,21 @@ struct result
     // F: E -> F
     // retval: result<T, F>
     template<typename F>
-    result<value_type, return_type_of_t<F, error_type&>>
+    result<value_type, detail::return_type_of_t<F, error_type&>>
     map_err(F&& f) &
     {
         if(this->is_err()){return err(f(this->as_err()));}
         return ok(this->as_ok());
     }
     template<typename F>
-    result<value_type, return_type_of_t<F, error_type const&>>
+    result<value_type, detail::return_type_of_t<F, error_type const&>>
     map_err(F&& f) const&
     {
         if(this->is_err()){return err(f(this->as_err()));}
         return ok(this->as_ok());
     }
     template<typename F>
-    result<value_type, return_type_of_t<F, error_type&&>>
+    result<value_type, detail::return_type_of_t<F, error_type&&>>
     map_err(F&& f) &&
     {
         if(this->is_err()){return err(f(std::move(this->as_err())));}
@@ -494,21 +479,21 @@ struct result
     // F: T -> U
     // retval: U
     template<typename F, typename U>
-    return_type_of_t<F, value_type&>
+    detail::return_type_of_t<F, value_type&>
     map_or_else(F&& f, U&& opt) &
     {
         if(this->is_err()){return std::forward<U>(opt);}
         return f(this->as_ok());
     }
     template<typename F, typename U>
-    return_type_of_t<F, value_type const&>
+    detail::return_type_of_t<F, value_type const&>
     map_or_else(F&& f, U&& opt) const&
     {
         if(this->is_err()){return std::forward<U>(opt);}
         return f(this->as_ok());
     }
     template<typename F, typename U>
-    return_type_of_t<F, value_type&&>
+    detail::return_type_of_t<F, value_type&&>
     map_or_else(F&& f, U&& opt) &&
     {
         if(this->is_err()){return std::forward<U>(opt);}
@@ -519,21 +504,21 @@ struct result
     // F: E -> U
     // retval: U
     template<typename F, typename U>
-    return_type_of_t<F, error_type&>
+    detail::return_type_of_t<F, error_type&>
     map_err_or_else(F&& f, U&& opt) &
     {
         if(this->is_ok()){return std::forward<U>(opt);}
         return f(this->as_err());
     }
     template<typename F, typename U>
-    return_type_of_t<F, error_type const&>
+    detail::return_type_of_t<F, error_type const&>
     map_err_or_else(F&& f, U&& opt) const&
     {
         if(this->is_ok()){return std::forward<U>(opt);}
         return f(this->as_err());
     }
     template<typename F, typename U>
-    return_type_of_t<F, error_type&&>
+    detail::return_type_of_t<F, error_type&&>
     map_err_or_else(F&& f, U&& opt) &&
     {
         if(this->is_ok()){return std::forward<U>(opt);}
@@ -545,21 +530,21 @@ struct result
     // toml::err(error_type) should be convertible to U.
     // normally, type U is another result<S, F> and E is convertible to F
     template<typename F>
-    return_type_of_t<F, value_type&>
+    detail::return_type_of_t<F, value_type&>
     and_then(F&& f) &
     {
         if(this->is_ok()){return f(this->as_ok());}
         return err(this->as_err());
     }
     template<typename F>
-    return_type_of_t<F, value_type const&>
+    detail::return_type_of_t<F, value_type const&>
     and_then(F&& f) const&
     {
         if(this->is_ok()){return f(this->as_ok());}
         return err(this->as_err());
     }
     template<typename F>
-    return_type_of_t<F, value_type&&>
+    detail::return_type_of_t<F, value_type&&>
     and_then(F&& f) &&
     {
         if(this->is_ok()){return f(std::move(this->as_ok()));}
@@ -571,27 +556,47 @@ struct result
     // toml::ok(value_type) should be convertible to U.
     // normally, type U is another result<S, F> and T is convertible to S
     template<typename F>
-    return_type_of_t<F, error_type&>
+    detail::return_type_of_t<F, error_type&>
     or_else(F&& f) &
     {
         if(this->is_err()){return f(this->as_err());}
         return ok(this->as_ok());
     }
     template<typename F>
-    return_type_of_t<F, error_type const&>
+    detail::return_type_of_t<F, error_type const&>
     or_else(F&& f) const&
     {
         if(this->is_err()){return f(this->as_err());}
         return ok(this->as_ok());
     }
     template<typename F>
-    return_type_of_t<F, error_type&&>
+    detail::return_type_of_t<F, error_type&&>
     or_else(F&& f) &&
     {
         if(this->is_err()){return f(std::move(this->as_err()));}
         return ok(std::move(this->as_ok()));
     }
 
+    // if *this is error, returns *this. otherwise, returns other.
+    result and_other(const result& other) const&
+    {
+        return this->is_err() ? *this : other;
+    }
+    result and_other(result&& other) &&
+    {
+        return this->is_err() ? std::move(*this) : std::move(other);
+    }
+
+    // if *this is okay, returns *this. otherwise, returns other.
+    result or_other(const result& other) const&
+    {
+        return this->is_ok() ? *this : other;
+    }
+    result or_other(result&& other) &&
+    {
+        return this->is_ok() ? std::move(*this) : std::move(other);
+    }
+
     void swap(result<T, E>& other)
     {
         result<T, E> tmp(std::move(*this));
@@ -638,5 +643,22 @@ void swap(result<T, E>& lhs, result<T, E>& rhs)
     return;
 }
 
+// this might be confusing because it eagerly evaluated, while in the other
+// cases operator && and || are short-circuited.
+//
+// template<typename T, typename E>
+// inline result<T, E>
+// operator&&(const result<T, E>& lhs, const result<T, E>& rhs) noexcept
+// {
+//     return lhs.is_ok() ? rhs : lhs;
+// }
+//
+// template<typename T, typename E>
+// inline result<T, E>
+// operator||(const result<T, E>& lhs, const result<T, E>& rhs) noexcept
+// {
+//     return lhs.is_ok() ? lhs : rhs;
+// }
+
 } // toml11
 #endif// TOML11_RESULT_H

toml/traits.hpp

@@ -15,6 +15,9 @@ namespace detail
 template<typename T>
 using unwrap_t = typename std::decay<T>::type;
 
+// ---------------------------------------------------------------------------
+// check whether type T is a kind of container/map class
+
 struct has_iterator_impl
 {
     template<typename T> static std::true_type  check(typename T::iterator*);
@@ -63,6 +66,9 @@ struct has_resize_method : decltype(has_resize_method_impl::check<T>(nullptr)){}
 #undef decltype(...)
 #endif
 
+// ---------------------------------------------------------------------------
+// C++17 and/or/not
+
 template<typename ...> struct conjunction : std::true_type{};
 template<typename T>   struct conjunction<T> : T{};
 template<typename T, typename ... Ts>
@@ -80,6 +86,9 @@ struct disjunction<T, Ts...> :
 template<typename T>
 struct negation : std::integral_constant<bool, !static_cast<bool>(T::value)>{};
 
+// ---------------------------------------------------------------------------
+// normal type checker
+
 template<typename T> struct is_std_pair : std::false_type{};
 template<typename T1, typename T2>
 struct is_std_pair<std::pair<T1, T2>> : std::true_type{};
@@ -92,7 +101,9 @@ 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{};
 
-// to use toml::get<std::tuple<T1, T2, ...>> in C++11
+// ---------------------------------------------------------------------------
+// C++14 index_sequence
+
 template<std::size_t ... Ns> struct index_sequence{};
 
 template<typename IS, std::size_t N> struct push_back_index_sequence{};
@@ -116,6 +127,21 @@ struct index_sequence_maker<0>
 template<std::size_t N>
 using make_index_sequence = typename index_sequence_maker<N-1>::type;
 
+// ---------------------------------------------------------------------------
+// return_type_of_t
+
+#if __cplusplus >= 201703L
+
+template<typename F, typename ... Args>
+using return_type_of_t = std::invoke_result_t<F, Args...>;
+
+#else
+// result_of is deprecated after C++17
+template<typename F, typename ... Args>
+using return_type_of_t = typename std::result_of<F(Args...)>::type;
+
+#endif
+
 }// detail
 }//toml
 #endif // TOML_TRAITS

toml/types.hpp

@@ -137,17 +137,6 @@ template<> struct toml_value_t<LocalDate     >{static constexpr value_t value =
 template<> struct toml_value_t<LocalTime     >{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> constexpr value_t toml_value_t<T>::value;
-constexpr value_t toml_value_t<Boolean       >::value;
-constexpr value_t toml_value_t<Integer       >::value;
-constexpr value_t toml_value_t<Float         >::value;
-constexpr value_t toml_value_t<String        >::value;
-constexpr value_t toml_value_t<OffsetDatetime>::value;
-constexpr value_t toml_value_t<LocalDatetime >::value;
-constexpr value_t toml_value_t<LocalDate     >::value;
-constexpr value_t toml_value_t<LocalTime     >::value;
-constexpr value_t toml_value_t<Array         >::value;
-constexpr value_t toml_value_t<Table         >::value;
 
 template<typename T>
 struct is_exact_toml_type : disjunction<

toml/value.hpp

@@ -767,6 +767,8 @@ inline bool operator<(const toml::value& lhs, const toml::value& rhs)
             return lhs.cast<value_t::Float   >() < rhs.cast<value_t::Float   >();
         case value_t::String  :
             return lhs.cast<value_t::String  >() < rhs.cast<value_t::String  >();
+        case value_t::OffsetDatetime:
+            return lhs.cast<value_t::OffsetDatetime>() < rhs.cast<value_t::OffsetDatetime>();
         case value_t::LocalDatetime:
             return lhs.cast<value_t::LocalDatetime>() < rhs.cast<value_t::LocalDatetime>();
         case value_t::LocalDate:
@@ -801,17 +803,21 @@ inline bool operator>=(const toml::value& lhs, const toml::value& rhs)
 }
 
 inline std::string format_error(const std::string& err_msg,
-        const toml::value& v, const std::string& comment)
+        const toml::value& v, const std::string& comment,
+        std::vector<std::string> hints = {})
 {
-    return detail::format_underline(err_msg, detail::get_region(v), comment);
+    return detail::format_underline(err_msg, detail::get_region(v), comment,
+                                    std::move(hints));
 }
 
 inline std::string format_error(const std::string& err_msg,
         const toml::value& v1, const std::string& comment1,
-        const toml::value& v2, const std::string& comment2)
+        const toml::value& v2, const std::string& comment2,
+        std::vector<std::string> hints = {})
 {
     return detail::format_underline(err_msg, detail::get_region(v1), comment1,
-                                             detail::get_region(v2), comment2);
+                                             detail::get_region(v2), comment2,
+                                             std::move(hints));
 }
 
 }// toml