https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82611
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |INVALID Status|UNCONFIRMED |RESOLVED --- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- https://gcc.gnu.org/pipermail/gcc-patches/2011-June/315878.html So basically GCC decided to make it a warning rather than a hard error even though the standard says it is illformed.