https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84139
--- Comment #2 from Christopher Di Bella <cjdb.ns at gmail dot com> --- An observation by Casey Carter (maintainer for cmcstl2) was made over at cpplang.slack.org#concepts: > Presumably a concepts bug being triggered in the > `std::iterator_traits`-hooking code at > https://github.com/CaseyCarter/cmcstl2/blob/master/include/stl2/detail/iterator/concepts.hpp#L781
