Another thought is that I happened to realize that an unexpected standard was used because I saw in my compile line a -std=c++17 while I requested a c++14. As the command line is constructed by CMake it should be it that is adding the option? Isn’t it? In this case there must be some compiler inspection within CMake that helps to get that?
A.
[EDIT] on a minimal example, inspecting CMAKE variable produced during configuration and generation, I found these ones:
-- CMAKE_CXX_STANDARD_COMPUTED_DEFAULT=17
-- CMAKE_CXX_STANDARD_DEFAULT=17
Can’t they be used? I don’t know from which point they are available yet.
[EDIT2] They don’t seem to be documented…