https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114536
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Fedor Chelnokov from comment #2) > May be just fail constant evaluation then instead of evaluating it to 0? I suspect gcc is not rejecting it because the struct is just one unsigned char and it is getting confused between that and the unsigned char.