https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67777
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- This is a GNU extension, use -Wpedantic or -Werror=pedantic to get a diagnostic. The diagnostic is not enormously helpful though: w.cc:1:17: warning: long, short, signed or unsigned used invalidly for ‘parameter’ [-Wpedantic]
