https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119280
--- Comment #8 from Sam James <sjames at gcc dot gnu.org> --- If something behaves identically in GCC and in Clang, that usually means it's UB (or some intentional behaviour, or both). You can style it as a feature request but something fundamental isn't going to change like that in most cases (including here).
