https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94038
--- Comment #2 from Patrick Palka <ppalka at gcc dot gnu.org> --- (In reply to Marek Polacek from comment #1) > > This seems to be a regression from GCC 9. > > Are you sure? I see the same thing with GCC 6. Oops, you're right, it's not a regression.