1 // RUN: %clang_cc1 -std=c++2a -x c++ %s -verify
2 
3 namespace type
4 {
5   template<typename T>
6   concept C1 = true;
7 
8   template<C1 T, C1 U = int>
9   using A = T[10];
10 
11   using a = A<int>;
12 
13   namespace ns {
14     template<typename T, int a = 0>
15     concept C2 = true;
16   }
17 
18   template<ns::C2 T1, ::type::ns::C2 T2> requires (sizeof(T1) <= sizeof(T2))
19   struct B { };
20 
21   using b = B<int, int>;
22 
23   template<ns::C2... T1>
24   struct C { };
25 
26   using c1 = C<char, char, char>;
27   using c2 = C<char, char, char, char>;
28 }
29 
30 namespace non_type
31 {
32   template<int v>
33   concept C1 = true;
34 
35   template<C1 v, C1 u = 0> // expected-error{{expected a type}} // expected-note{{declared here}}
36   // expected-error@-1 2{{concept named in type constraint is not a type concept}}
37   // expected-error@-2 {{expected ',' or '>' in template-parameter-list}}
38   int A = v; // expected-error{{'v' does not refer to a value}}
39 }
40 
41 namespace temp
42 {
43   template<typename>
44   struct test1 { }; // expected-note{{template is declared here}}
45 
46   template<template<typename> typename T>
47   concept C1 = true;
48 
49   template<C1 TT, C1 UU = test1> // expected-error{{use of class template 'test1' requires template arguments}}
50   // expected-error@-1 2{{concept named in type constraint is not a type concept}}
51   using A = TT<int>; // expected-error{{expected ';' after alias declaration}}
52 }