1 // Support parsing of concepts
2 
3 // RUN:  %clang_cc1 -std=c++2a -fconcepts-ts -verify %s
4 template<typename T> concept C1 = true; // expected-note 2{{previous}}
5 
6 template<typename T> concept C1 = true; // expected-error{{redefinition}}
7 
8 template<concept T> concept D1 = true;
9 // expected-error@-1{{expected template parameter}}
10 // expected-error@-2{{concept template parameter list must have at least one parameter; explicit specialization of concepts is not allowed}}
11 
12 template<template<typename> concept T> concept D2 = true;
13 // expected-error@-1{{expected identifier}}
14 // expected-error@-2{{template template parameter requires 'class' after the parameter list}}
15 // expected-error@-3{{concept template parameter list must have at least one parameter; explicit specialization of concepts is not allowed}}
16 
17 template<typename T> concept C2 = 0.f; // expected-error {{constraint expression must be of type 'bool' but is of type 'float'}}
18 
19 struct S1 {
20   template<typename T> concept C1 = true; // expected-error {{concept declarations may only appear in global or namespace scope}}
21 };
22 
23 extern "C++" {
24   template<typename T> concept C1 = true; // expected-error{{redefinition}}
25 }
26 
27 template<typename A>
28 template<typename B>
29 concept C4 = true; // expected-error {{extraneous template parameter list in concept definition}}
30 
31 template<typename T> concept C5 = true; // expected-note {{previous}} expected-note {{previous}}
32 int C5; // expected-error {{redefinition}}
33 struct C5 {}; // expected-error {{redefinition}}
34 
35 struct C6 {}; // expected-note{{previous definition is here}}
36 template<typename T> concept C6 = true;
37 // expected-error@-1{{redefinition of 'C6' as different kind of symbol}}
38 
39 // TODO: Add test to prevent explicit specialization, partial specialization
40 // and explicit instantiation of concepts.
41 
42 template<typename T, T v>
43 struct integral_constant { static constexpr T value = v; };
44 
45 namespace N {
46   template<typename T> concept C7 = true;
47 }
48 using N::C7;
49 
50 template <bool word> concept C8 = integral_constant<bool, wor>::value;
51 // expected-error@-1{{use of undeclared identifier 'wor'; did you mean 'word'?}}
52 // expected-note@-2{{'word' declared here}}
53 
54 template<typename T> concept bool C9 = true;
55 // expected-warning@-1{{ISO C++2a does not permit the 'bool' keyword after 'concept'}}
56 
57 template<> concept C10 = false;
58 // expected-error@-1{{concept template parameter list must have at least one parameter; explicit specialization of concepts is not allowed}}
59 
60 template<> concept C9<int> = false;
61 // expected-error@-1{{name defined in concept definition must be an identifier}}
62 
63 template<typename T> concept N::C11 = false;
64 // expected-error@-1{{name defined in concept definition must be an identifier}}
65 
66 class A { };
67 // expected-note@-1{{'A' declared here}}
68 
69 template<typename T> concept A::C12 = false;
70 // expected-error@-1{{expected namespace name}}
71 
72 template<typename T> concept operator int = false;
73 // expected-error@-1{{name defined in concept definition must be an identifier}}
74