https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85282
--- Comment #21 from Jason Merrill <jason at gcc dot gnu.org> --- (In reply to Jason Merrill from comment #13) > I vaguely remember us supporting this in the distant past, but removing that > support to be conforming. > > Ah, yes, in 1998: r0-18485 And before that, r22271 . I'm adding this to the C++17 section of cxx-status.