https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80648
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> --- Whether or not it's part of the standard has no bearing on whether it's a bug in GCC, because we don't claim to implement just the original published standard. GCC's policy is to implement the standard plus DRs. It's a DR, so the fact we implement it is not a GCC bug, it's policy.
