https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70979
--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> --- Created attachment 40731 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40731&action=edit patch for DR 1071 Relatedly, here's a patch to implement DR 1071, which is the error clang gives. But this breaks several things in libstdc++, so it needs more investigation before it will be ready even for GCC 8.
