https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89612
--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> --- And a better testcase, and actually valid: template <typename> struct C { template <int N> friend int foo() noexcept(N); }; template <int N> int foo() noexcept(N); C<int> c;