https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98639
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Whether it is valid or not will defer to language lawyers. It started to be accepted with r10-5137-g43aae289866f5ea55d187444520412554aa2e171 aka P0960R3 implementation. And clang doesn't seem to implement P0960R3 yet, so not surprisingly it rejects it.