clang/test/Parser/friend-concept.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
   2
   3 template<class>
   4 concept fooable = true;
   5
   6 struct S {
   7   template<class> friend concept x = requires { requires true; }; // expected-error {{friend declaration cannot be a concept}}
   8   template<class> friend concept fooable; // expected-error {{friend declaration cannot be a concept}}
   9   template<class> concept friend fooable; // expected-error {{expected unqualified-id}}
  10   friend concept fooable; // expected-error {{friend declaration cannot be a concept}}
  11   concept friend fooable; // expected-error {{friend declaration cannot be a concept}}
  12   concept fooable; // expected-error {{concept declarations may only appear in global or namespace scope}}
  13 };