As an aside, it would also be useful to check inside the SDL2Config.cmake config file whether the CXX language is actually enabled.
Because if it is not, the build process will fail at a later time.
See e.g. this issue I created earlier this year.

I think the cmake config file might need something like:

include(CheckLanguage)
check_language(CXX)
if(NOT CMAKE_CXX_COMPILER)
    message(WARNING "SDL2 requires CXX, but it not enabled.")
endif()

CheckLanguage documentation

Or skip the warning and do enable_language(CXX) yourself.

Originally posted by @madebr in #161 (comment)