https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54924
--- Comment #11 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #10) > I'm starting to think we should just make libstdc++ headers 100% > warning-free and stop marking them as system headers with the pragmas. When > they're installed under /usr they'd still be considered system headers > though. Invent #pragma not_system_header ? But being a system header is sometimes also used to enable extensions, which may still be useful for libstdc++ headers.