https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108884
--- Comment #2 from Younan Zhang <zyn7109 at gmail dot com> --- (In reply to Patrick Palka from comment #1) > #1 is neither a non-template friend declaration with a requires-clause nor a > friend function template with a constraint that depends on a template > parameter from an enclosing template, so it seems to me [temp.friend]/9 > doesn't apply here? I'm a bit confused. Doesn't `friend auto factory(const C auto&...)` equal to template where `Us` depends on parameter from outter C? ```cpp template <C... Us> friend auto factory(const C Us&...);` ```
