https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65913 --- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> --- Richard's patch in comment 2 doesn't seem to help, the testcase with std::atomic<Simple>::is_lock_free() still fails to link, as does the simplest case, std::atomic<int>::is_lock_free()