68 lines
1.8 KiB
C++
68 lines
1.8 KiB
C++
// RUN: %clang_cc1 -std=c++2a -x c++ %s -verify
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using A = int;
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template<typename T, typename U>
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constexpr bool is_same_v = false;
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template<typename T>
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constexpr bool is_same_v<T, T> = true;
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template<typename T, typename U>
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concept same_as = is_same_v<T, U>;
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static_assert(requires { requires true; 0; typename A;
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{ 0 } -> same_as<int>; });
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static_assert(is_same_v<bool, decltype(requires { requires false; })>);
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// Check that requires expr is an unevaluated context.
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struct Y {
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int i;
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static constexpr bool r = requires { i; };
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};
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template<typename T> requires requires (T t) {
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requires false; // expected-note{{because 'false' evaluated to false}}
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requires false;
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requires requires {
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requires false;
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};
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}
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struct r1 { };
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using r1i = r1<int>;
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// expected-error@-1 {{constraints not satisfied for class template 'r1' [with T = int]}}
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template<typename T> requires requires (T t) {
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requires requires {
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requires false; // expected-note{{because 'false' evaluated to false}}
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};
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}
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struct r2 { };
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using r2i = r2<int>;
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// expected-error@-1 {{constraints not satisfied for class template 'r2' [with T = int]}}
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template<typename T> requires requires (T t) {
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requires requires {
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requires true;
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};
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requires true;
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requires requires {
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requires false; // expected-note{{because 'false' evaluated to false}}
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};
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}
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struct r3 { };
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using r3i = r3<int>;
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// expected-error@-1 {{constraints not satisfied for class template 'r3' [with T = int]}}
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template<typename T>
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struct S { static const int s = T::value; };
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template<typename T> requires requires { T::value; S<T>::s; }
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// expected-note@-1 {{because 'T::value' would be invalid: type 'int' cannot be used prior to '::' because it has no members}}
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struct r4 { };
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using r4i = r4<int>;
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// expected-error@-1 {{constraints not satisfied for class template 'r4' [with T = int]}}
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