<!-- This issue tracker is for CMake upstream development: * If you are having trouble building a specific third-party project that uses CMake, ask for help in that project's forums first. * If you have a coding or usage question, please ask for help on the CMake discourse forums: https://discourse.cmake.org/ --> ## Description When we generate `moc_predefs.h` headers for every target we have, predefines should be generated/modified according to the target's `CXX_STANDARD`. In our current situation, It is generated by using the compiler's default C++ standard. ## Possible Solution The `CMAKE_CXX_COMPILER_PREDEFINES_COMMAND` should have an argument related to C++ standard either in `Modules/Compiler/*.cmake` or `cmQtAutoGenInitializer.cxx`