https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82081
--- Comment #8 from Jason Merrill <jason at gcc dot gnu.org> --- Created attachment 46157 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46157&action=edit fix Here's a patch. I'm not sure if it will go into GCC 9 or 10.