https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67016
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- EDG also gives no diagnostic and Clang says it's a GNU extension.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67016
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- EDG also gives no diagnostic and Clang says it's a GNU extension.