This patch consistently changes the inclusion order for unit test files
to the following:
1. The header of the unit under test (using <> includes).
2. The unit_test.hpp header (using "" includes).
3. Any additional auxiliary test headers (using "" includes and sorted alphabetically).
4. Additional system headers needed for the test (using <> includes and sorted alphabetically).
5. Conditionally included system headers (using <> includes).
Putting the unit under test's header at the very beginning has the
advantage of also testing that the header is self-contained. It also
makes it very quick to tell what unit is tested in this file.
This removes one #define from each unit test file and ensures
consistency between file and module names. This consistency, was not
strictly maintained before. I hope that any discrepancies were
unintentional and that a 1:1 mapping is actually what is desired.
Since the definition is now done at one single place, it would be easy
to apply transformations like removing the 'test_' prefix or replacing
'_' with '-' if this should be desired.
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.
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.
