test: Correct C++ compilation tests
# This CMake script creates multiple additional targets to test the compilation of public headers
# with different C and C++ standards.
-set(standards c_std_99;c_std_11;cxx_std_14)
-if(NOT CMAKE_CXX_COMPILER_ID STREQUAL Clang OR CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 3.8.1)
- list(APPEND standards cxx_std_17)
-endif()
+set(standards c_std_99;c_std_11;cxx_std_17;cxx_std_20)
list(APPEND all_features ${CMAKE_CXX_COMPILE_FEATURES})
list(APPEND all_features ${CMAKE_C_COMPILE_FEATURES})
