# Enable scanning by default for targets that explicitly use C++ 20. cmake_policy(SET CMP0155 NEW) enable_language(CXX) # Hide any real scanning rule that may be available. unset(CMAKE_CXX_SCANDEP_SOURCE) # Explicitly enable C++20 for all targets. set(CMAKE_CXX_STANDARD 20) set(CMAKE_CXX_STANDARD_REQUIRED ON) # Explicitly suppress scanning so that support is not required. set(CMAKE_CXX_SCAN_FOR_MODULES OFF) add_executable(noscanning-variable main-no-use.cxx) # Verify that CMAKE_CXX_SCAN_FOR_MODULES is propagated into the check. # FIXME: Unset CMAKE_CXX_SCANDEP_SOURCE inside try_compile so this # test can verify behavior on newer compilers too. try_compile(result SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/main-no-use.cxx)