https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116162
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Not really sure if this paper was a DR or not. Seems clang rejects this for -std=c++17 and earlier and accepts with a warning for -std=c++20 and later, what we probably should do is silently make it deleted and when something attempts to use the deleted function, next to the normal diagnostics emit explanation why it was deleted.
