https://en.cppreference.com/w/cpp/compiler_support says that this is supported in GCC >= 11 CLANG >= 16 Visual Studio >= VS 2019 16.10 And our Visual Studio baseline is now 2019. We still need to make the ifdef conditional check clang, because __has_include will happily return true even if the current clang does not support the necessary builtins. Change-Id: I5f2743e204b8ed22d4651053f3ae579a4a192a45 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/157515 Tested-by: Jenkins Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>