https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86009
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Trunk now says:
86009.cc:3:11: error: expected 'auto' or 'decltype(auto)' after 'C1'
3 | void f(C0<C1> *) { }
| ^~
86009.cc:3:8: error: expected 'auto' or 'decltype(auto)' after 'C0<auto:1>'
3 | void f(C0<C1> *) { }
| ^~~~~~
86009.cc:5:15: error: template-id 'f<wchar_t, short int>' for 'void
f(wchar_t*)' does not match any template declaration
5 | template void f<wchar_t, short>(wchar_t *);
| ^~~~~~~~~~~~~~~~~
86009.cc:3:6: note: candidate is: 'template<class auto:1, class auto:2>
requires (C1<auto:1>) && (C0<auto:2, auto:1>) void f(auto:2*)'
3 | void f(C0<C1> *) { }
| ^
