Add functions for creating tests and to supply test- and
standard-specific build settings.
Raises minimum CMake version to 3.13 in test directory.
json_test_add_test_for(
<file>
MAIN <main>
[CXX_STANDARDS <version_number>...] [FORCE])
Given a <file> unit-foo.cpp, produces
test-foo_cpp<version_number>
if C++ standard <version_number> is supported by the compiler and
thesource file contains JSON_HAS_CPP_<version_number>. Use FORCE to
create the test regardless of the file containing
JSON_HAS_CPP_<version_number>. Test targets are linked against <main>.
CXX_STANDARDS defaults to "11".
json_test_set_test_options(
all|<tests>
[CXX_STANDARDS all|<args>...]
[COMPILE_DEFINITIONS <args>...]
[COMPILE_FEATURES <args>...]
[COMPILE_OPTIONS <args>...]
[LINK_LIBRARIES <args>...]
[LINK_OPTIONS <args>...])
Supply test- and standard-specific build settings.
Specify multiple tests using a list e.g., "test-foo;test-bar".
Must be called BEFORE the test is created.
