https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93983
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- See Also| |https://gcc.gnu.org/bugzill | |a/show_bug.cgi?id=93923 --- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- This is nothing to do with concepts: #include <iterator> struct path { template <typename Source, typename = std::enable_if_t< std::is_same_v< std::iterator_traits<Source>::value_type, char>> > path(Source const&); }; struct Bar { Bar(const path& p); }; #ifdef ADD_THIS static_assert(!std::is_constructible_v<path, Bar>); #endif static_assert(std::is_copy_constructible_v<Bar>); See also PR 93923.