https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102839
--- Comment #4 from Martin Liška <marxin at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #2) > Martin, did you use -stdlib=libc++ with Clang? Otherwise you're just testing > libstdc++ again with a different compiler. I didn't, my bad. Will do it next time. Thanks.