| // RUN: %clang_cc1 -std=c++17 -verify %s |
| // RUN: %clang_cc1 -std=c++17 -verify %s -DNO_CONSTEXPR |
| // RUN: %clang_cc1 -std=c++20 -verify %s |
| |
| namespace std { |
| #ifndef NO_CONSTEXPR |
| #define CONSTEXPR constexpr |
| #else |
| #define CONSTEXPR |
| #endif |
| |
| template<typename T> CONSTEXPR T &&move(T &x) { |
| static_assert(T::moveable, "instantiated move"); // expected-error {{no member named 'moveable' in 'B'}} |
| // expected-error@-1 {{no member named 'moveable' in 'C'}} |
| return static_cast<T&&>(x); |
| } |
| |
| // Unrelated move functions are not the builtin. |
| template<typename T> CONSTEXPR int move(T, T) { return 5; } |
| |
| template<typename T, bool Rref> struct ref { using type = T&; }; |
| template<typename T> struct ref<T, true> { using type = T&&; }; |
| |
| template<typename T> CONSTEXPR auto move_if_noexcept(T &x) -> typename ref<T, noexcept(T(static_cast<T&&>(x)))>::type { |
| static_assert(T::moveable, "instantiated move_if_noexcept"); // expected-error {{no member named 'moveable' in 'B'}} |
| return static_cast<typename ref<T, noexcept(T(static_cast<T&&>(x)))>::type>(x); |
| } |
| |
| template<typename T> struct remove_reference { using type = T; }; |
| template<typename T> struct remove_reference<T&> { using type = T; }; |
| template<typename T> struct remove_reference<T&&> { using type = T; }; |
| |
| template<typename T> struct is_lvalue_reference { static constexpr bool value = false; }; |
| template<typename T> struct is_lvalue_reference<T&> { static constexpr bool value = true; }; |
| |
| template<typename T> CONSTEXPR T &&forward(typename remove_reference<T>::type &x) { |
| static_assert(T::moveable, "instantiated forward"); // expected-error {{no member named 'moveable' in 'B'}} |
| // expected-error@-1 {{no member named 'moveable' in 'C'}} |
| return static_cast<T&&>(x); |
| } |
| template<typename T> CONSTEXPR T &&forward(typename remove_reference<T>::type &&x) { |
| static_assert(!is_lvalue_reference<T>::value, "should not forward rval as lval"); // expected-error {{static assertion failed}} |
| return static_cast<T&&>(x); |
| } |
| |
| template<typename T> CONSTEXPR const T &as_const(T &x) { |
| static_assert(T::moveable, "instantiated as_const"); // expected-error {{no member named 'moveable' in 'B'}} |
| return x; |
| } |
| |
| template<typename T> CONSTEXPR T *addressof(T &x) { |
| static_assert(T::moveable, "instantiated addressof"); // expected-error {{no member named 'moveable' in 'B'}} |
| return __builtin_addressof(x); |
| } |
| |
| template<typename T> CONSTEXPR T *__addressof(T &x) { |
| static_assert(T::moveable, "instantiated __addressof"); // expected-error {{no member named 'moveable' in 'B'}} |
| return __builtin_addressof(x); |
| } |
| } |
| |
| // Note: this doesn't have a 'moveable' member. Instantiation of the above |
| // functions will fail if it's attempted. |
| struct A {}; |
| constexpr bool f(A a) { // #f |
| A &&move = std::move(a); // #call |
| A &&move_if_noexcept = std::move_if_noexcept(a); |
| A &&forward1 = std::forward<A>(a); |
| A &forward2 = std::forward<A&>(a); |
| const A &as_const = std::as_const(a); |
| A *addressof = std::addressof(a); |
| A *addressof2 = std::__addressof(a); |
| return &move == &a && &move_if_noexcept == &a && |
| &forward1 == &a && &forward2 == &a && |
| &as_const == &a && addressof == &a && |
| addressof2 == &a && std::move(a, a) == 5; |
| } |
| |
| #ifndef NO_CONSTEXPR |
| static_assert(f({}), "should be constexpr"); |
| #else |
| // expected-error@#f {{never produces a constant expression}} |
| // expected-note@#call {{}} |
| #endif |
| |
| A &forward_rval_as_lval() { |
| std::forward<A&&>(A()); // expected-warning {{const attribute}} |
| return std::forward<A&>(A()); // expected-note {{instantiation of}} expected-warning {{returning reference}} |
| } |
| |
| struct B {}; |
| B &&(*pMove)(B&) = std::move; // #1 expected-note {{instantiation of}} |
| B &&(*pMoveIfNoexcept)(B&) = &std::move_if_noexcept; // #2 expected-note {{instantiation of}} |
| B &&(*pForward)(B&) = &std::forward<B>; // #3 expected-note {{instantiation of}} |
| const B &(*pAsConst)(B&) = &std::as_const; // #4 expected-note {{instantiation of}} |
| B *(*pAddressof)(B&) = &std::addressof; // #5 expected-note {{instantiation of}} |
| B *(*pUnderUnderAddressof)(B&) = &std::__addressof; // #6 expected-note {{instantiation of}} |
| int (*pUnrelatedMove)(B, B) = std::move; |
| |
| struct C {}; |
| C &&(&rMove)(C&) = std::move; // #7 expected-note {{instantiation of}} |
| C &&(&rForward)(C&) = std::forward<C>; // #8 expected-note {{instantiation of}} |
| int (&rUnrelatedMove)(B, B) = std::move; |
| |
| #if __cplusplus <= 201703L |
| // expected-warning@#1 {{non-addressable}} |
| // expected-warning@#2 {{non-addressable}} |
| // expected-warning@#3 {{non-addressable}} |
| // expected-warning@#4 {{non-addressable}} |
| // expected-warning@#5 {{non-addressable}} |
| // expected-warning@#6 {{non-addressable}} |
| // expected-warning@#7 {{non-addressable}} |
| // expected-warning@#8 {{non-addressable}} |
| #else |
| // expected-error@#1 {{non-addressable}} |
| // expected-error@#2 {{non-addressable}} |
| // expected-error@#3 {{non-addressable}} |
| // expected-error@#4 {{non-addressable}} |
| // expected-error@#5 {{non-addressable}} |
| // expected-error@#6 {{non-addressable}} |
| // expected-error@#7 {{non-addressable}} |
| // expected-error@#8 {{non-addressable}} |
| #endif |
| |
| void attribute_const() { |
| int n; |
| std::move(n); // expected-warning {{ignoring return value}} |
| std::move_if_noexcept(n); // expected-warning {{ignoring return value}} |
| std::forward<int>(n); // expected-warning {{ignoring return value}} |
| std::addressof(n); // expected-warning {{ignoring return value}} |
| std::__addressof(n); // expected-warning {{ignoring return value}} |
| std::as_const(n); // expected-warning {{ignoring return value}} |
| } |
| |
| namespace std { |
| template<typename T> int &move(T); |
| } |
| int bad_signature = std::move(0); // expected-error {{unsupported signature for 'std::move<int>'}} |