CXXFLAGS -------- .. include:: ENV_VAR.txt Default compilation flags to be used when compiling ``CXX`` (C++) files. Will only be used by CMake on the first configuration to determine ``CXX`` default compilation flags, after which the value for ``CXXFLAGS`` is stored in the cache as :variable:`CMAKE_CXX_FLAGS _FLAGS>`. For any configuration run ( including the first), the environment variable will be ignored if the :variable:`CMAKE_CXX_FLAGS _FLAGS>` variable is defined. See also :variable:`CMAKE_CXX_FLAGS_INIT _FLAGS_INIT>`.