https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116492
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- >The same does not happen in clang, and in gcc with similar examples from other >classes I have tried. So it comes down to the concept on the constructor which is why you didn't run into similar examples from other classes. std::expected has requires statements on the constructors in some cases.
