https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99795
--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> --- Created attachment 50524 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50524&action=edit WIP Fix This patch uses IMPLICIT_CONV_EXPR to get the narrowing error, but more and more changes are being necessary to prevent regressions; this isn't going to be safe for GCC 11 at this point, so I'm going to put it aside for now.