1 // RUN: %clang_cc1 -std=c++20 -verify %s
2 
3 namespace PR47043 {
4   template<typename T> concept True = true;
5   template<typename ...T> concept AllTrue1 = True<T>; // expected-error {{expression contains unexpanded parameter pack 'T'}}
6   template<typename ...T> concept AllTrue2 = (True<T> && ...);
7   static_assert(AllTrue2<int, float, char>);
8 }
9 
10 namespace PR47025 {
11   template<typename ...T> concept AllAddable1 = requires(T ...t) { (void(t + 1), ...); };
12   template<typename ...T> concept AllAddable2 = (requires(T ...t) { (t + 1); } && ...); // expected-error {{requirement contains unexpanded parameter pack 't'}}
13   template<typename ...T> concept AllAddable3 = (requires(T t) { (t + 1); } && ...);
14   template<typename ...T> concept AllAddable4 = requires(T t) { (t + 1); }; // expected-error {{expression contains unexpanded parameter pack 'T'}}
15   template<typename ...T> concept AllAddable5 = requires(T t) { (void(t + 1), ...); }; // expected-error {{does not contain any unexpanded}}
16   template<typename ...T> concept AllAddable6 = (requires { (T() + 1); } && ...);
17   template<typename ...T> concept AllAddable7 = requires { (T() + 1); }; // expected-error {{expression contains unexpanded parameter pack 'T'}}
18 
19   static_assert(AllAddable1<int, float>);
20   static_assert(AllAddable3<int, float>);
21   static_assert(AllAddable6<int, float>);
22   static_assert(!AllAddable1<int, void>);
23   static_assert(!AllAddable3<int, void>);
24   static_assert(!AllAddable6<int, void>);
25 }
26