93 lines
4.7 KiB
C++
93 lines
4.7 KiB
C++
// RUN: %clang_cc1 -std=c++2a -x c++ -verify %s
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template<typename T> requires (sizeof(T) >= 2) // expected-note{{because 'sizeof(char) >= 2' (1 >= 2) evaluated to false}}
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struct A {
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static constexpr int value = sizeof(T);
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};
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static_assert(A<int>::value == 4);
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static_assert(A<char>::value == 1); // expected-error{{constraints not satisfied for class template 'A' [with T = char]}}
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template<typename T, typename U>
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requires (sizeof(T) != sizeof(U) // expected-note{{because 'sizeof(int) != sizeof(char [4])' (4 != 4) evaluated to false}}
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&& sizeof(T) >= 4) // expected-note{{because 'sizeof(char) >= 4' (1 >= 4) evaluated to false}}
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constexpr int SizeDiff = sizeof(T) > sizeof(U) ? sizeof(T) - sizeof(U) : sizeof(U) - sizeof(T);
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static_assert(SizeDiff<int, char> == 3);
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static_assert(SizeDiff<int, char[4]> == 0); // expected-error{{constraints not satisfied for variable template 'SizeDiff' [with T = int, U = char [4]]}}
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static_assert(SizeDiff<char, int> == 3); // expected-error{{constraints not satisfied for variable template 'SizeDiff' [with T = char, U = int]}}
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template<typename... Ts>
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requires ((sizeof(Ts) == 4) || ...) // expected-note{{because 'sizeof(char) == 4' (1 == 4) evaluated to false}} expected-note{{'sizeof(long long) == 4' (8 == 4) evaluated to false}} expected-note{{'sizeof(int [20]) == 4' (80 == 4) evaluated to false}}
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constexpr auto SumSizes = (sizeof(Ts) + ...);
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static_assert(SumSizes<char, long long, int> == 13);
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static_assert(SumSizes<char, long long, int[20]> == 89); // expected-error{{constraints not satisfied for variable template 'SumSizes' [with Ts = <char, long long, int [20]>]}}
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template<typename T>
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concept IsBig = sizeof(T) > 100; // expected-note{{because 'sizeof(int) > 100' (4 > 100) evaluated to false}}
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template<typename T>
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requires IsBig<T> // expected-note{{'int' does not satisfy 'IsBig'}}
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using BigPtr = T*;
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static_assert(sizeof(BigPtr<int>)); // expected-error{{constraints not satisfied for alias template 'BigPtr' [with T = int]}}}}
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template<typename T> requires T::value // expected-note{{because substituted constraint expression is ill-formed: type 'int' cannot be used prior to '::' because it has no members}}
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struct S { static constexpr bool value = true; };
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struct S2 { static constexpr bool value = true; };
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static_assert(S<int>::value); // expected-error{{constraints not satisfied for class template 'S' [with T = int]}}
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static_assert(S<S2>::value);
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template<typename T>
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struct AA
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{
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template<typename U> requires (sizeof(U) == sizeof(T)) // expected-note{{because 'sizeof(int [2]) == sizeof(int)' (8 == 4) evaluated to false}}
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struct B
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{
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static constexpr int a = 0;
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};
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template<typename U> requires (sizeof(U) == sizeof(T)) // expected-note{{because 'sizeof(int [2]) == sizeof(int)' (8 == 4) evaluated to false}}
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static constexpr int b = 1;
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template<typename U> requires (sizeof(U) == sizeof(T)) // expected-note{{because 'sizeof(int [2]) == sizeof(int)' (8 == 4) evaluated to false}}
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static constexpr int getB() { // expected-note{{candidate template ignored: constraints not satisfied [with U = int [2]]}}
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return 2;
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}
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static auto foo()
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{
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return B<T[2]>::a; // expected-error{{constraints not satisfied for class template 'B' [with U = int [2]]}}
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}
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static auto foo1()
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{
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return b<T[2]>; // expected-error{{constraints not satisfied for variable template 'b' [with U = int [2]]}}
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}
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static auto foo2()
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{
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return AA<T>::getB<T[2]>(); // expected-error{{no matching function for call to 'getB'}}
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}
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};
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constexpr auto x = AA<int>::foo(); // expected-note{{in instantiation of member function 'AA<int>::foo' requested here}}
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constexpr auto x1 = AA<int>::foo1(); // expected-note{{in instantiation of member function 'AA<int>::foo1' requested here}}
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constexpr auto x2 = AA<int>::foo2(); // expected-note{{in instantiation of member function 'AA<int>::foo2' requested here}}
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template<typename T>
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struct B { using type = typename T::type; }; // expected-error{{type 'int' cannot be used prior to '::' because it has no members}}
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template<typename T> requires B<T>::type // expected-note{{in instantiation of template class 'B<int>' requested here}}
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// expected-note@-1{{while substituting template arguments into constraint expression here}}
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struct C { };
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template<typename T> requires (T{}) // expected-error{{atomic constraint must be of type 'bool' (found 'int')}}
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struct D { };
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static_assert(C<int>{}); // expected-note{{while checking constraint satisfaction for template 'C<int>' required here}}
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static_assert(D<int>{}); // expected-note{{while checking constraint satisfaction for template 'D<int>' required here}}
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