bb78a0b334
Fixes #109538. In this patch, we introduce diagnostic for required expression parameters in the same way as function parameters, fix the issue of handling void type parameters, and align the behavior with GCC and other compilers.
83 lines
2.3 KiB
C++
83 lines
2.3 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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namespace GH109538 {
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static_assert(requires(void *t) { t; });
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static_assert(requires(void) { 42; });
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static_assert(requires(void t) { // expected-error {{argument may not have 'void' type}}
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t;
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});
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static_assert(requires(void t, int a) { // expected-error {{'void' must be the first and only parameter if specified}}
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t;
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});
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static_assert(requires(const void) { // expected-error {{'void' as parameter must not have type qualifiers}}
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42;
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});
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} // namespace GH109538
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