clang/test/SemaTemplate/GH71595.cpp

   1 // RUN: %clang_cc1 -std=c++20 -verify %s
   2
   3 template<class T, class U>
   4 concept C = true;
   5
   6 class non_temp {
   7     template<C<non_temp> T>
   8     friend void f();
   9
  10     non_temp();
  11 };
  12
  13 template<C<non_temp> T>
  14 void f() {
  15     auto v = non_temp();
  16 }
  17
  18 template<class A>
  19 class temp {
  20     template<C<temp> T>
  21     friend void g(); // expected-error {{friend declaration with a constraint that depends on an enclosing template parameter must be a definition}}
  22
  23     temp();
  24 };
  25
  26 template<C<temp<int>> T>
  27 void g() {
  28     auto v = temp<T>();
  29 }
  30
  31 void h() {
  32     f<int>();
  33     g<int>();
  34 }