Depending on the CMake and Boost version, the -Werror flags that might
get added to CMAKE_CXX_FLAGS could adversely affect the feature
detection logic, leading to the wrong conclusion that Boost.Test isn't
usable altogether. Performing these checks first and only afterwards
altering CMAKE_CXX_FLAGS avoids this issue.
The conditional inclusion of either the library or the header-only
version of the Boost.Test header wasn't tremendously useful in practice
because the tests/CMakeLists.txt file would unconditionally add compile
definitions to basically fore dynamic linking.
This patch adds feature detection to the tests/CMakeLists.txt file to
determine whether to use dynamic linking, static linking or the
header-only version (in that order of preference, for best performance).
The automatic detection could be overridden if needed by defining the
TOML11_WITH_BOOST_TEST_{HEADER,STATIC,DYNAMIC}
variables on the CMake command line.
While we are at it, instead of having a conditional
#define BOOST_TEST_NO_LIB
in each unit test file, handle this once in the CMakeLists.txt file.
Most unit test files checked UNITTEST_FRAMEWORK_LIBRARY_EXIST and
adapted themselves accordingly to either use the header-only version or
link with the library. Alas, eight files didn't so the project couldn't
really be tested with the header-only version of that Boost library.
This patch adds the missing pre-processor logic to the files that were
missing it. The style of using no indentation after the '#' was
followed from the existing unit test files. Some other files in this
repository do indent their pre-processor logic, though.
Since replicating the conditional in every file is kind of verbose,
tedious and, apparently, easily forgotten, I'm wondering whether
isolating that logic into a tiny little auxiliary header and then
unconditionally including that one in each unit test file would be a
good idea, though.
The fstream classes are notorious for their non-existent error handling.
This adds a C-style fILE * IO (fopen(), etc.) alternative interface, so
that if a user needs reliable error handling, they can use that, albeit
more inconvenient, but more robust approach.
When we add a macro to change the default comment preservation scheme,
some of the current tests that assume comments are discarded by defualt
fails. To make it more robust, we need to explicitly specify the comment
preservation scheme and add test cases for both of discard_ and
preserve_comments.
