| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20 |
| |
| // <utility> |
| |
| // template <class T1, class T2> struct pair |
| // template<class U1, class U2> constexpr |
| // const pair& operator=(const pair<U1, U2>& p) const; |
| |
| #include <cassert> |
| #include <utility> |
| |
| #include "test_macros.h" |
| #include "copy_move_types.h" |
| |
| // Constraints: |
| // is_assignable_v<const first_type&, const U1&> is true, and |
| // is_assignable_v<const second_type&, const U2&> is true. |
| |
| // clang-format off |
| static_assert( std::is_assignable_v<const std::pair<int&, int&>&, |
| const std::pair<long&, long&>&>); |
| static_assert(!std::is_assignable_v<const std::pair<int, int>&, |
| const std::pair<long, long>&>); |
| static_assert(!std::is_assignable_v<const std::pair<int, int&>&, |
| const std::pair<long, long&>&>); |
| static_assert(!std::is_assignable_v<const std::pair<int&, int>&, |
| const std::pair<long&, long>&>); |
| |
| static_assert(std::is_assignable_v< |
| const std::pair<AssignableFrom<ConstCopyAssign>, AssignableFrom<ConstCopyAssign>>&, |
| const std::pair<ConstCopyAssign, ConstCopyAssign>&>); |
| |
| static_assert(!std::is_assignable_v< |
| const std::pair<AssignableFrom<CopyAssign>, AssignableFrom<CopyAssign>>&, |
| const std::pair<CopyAssign, CopyAssign>&>); |
| // clang-format on |
| |
| constexpr bool test() { |
| // reference types |
| { |
| int i1 = 1; |
| int i2 = 2; |
| long j1 = 3; |
| long j2 = 4; |
| const std::pair<int&, int&> p1{i1, i2}; |
| const std::pair<long&, long&> p2{j1, j2}; |
| p2 = p1; |
| assert(p2.first == 1); |
| assert(p2.second == 2); |
| } |
| |
| // user defined const copy assignment |
| { |
| const std::pair<ConstCopyAssign, ConstCopyAssign> p1{1, 2}; |
| const std::pair<AssignableFrom<ConstCopyAssign>, AssignableFrom<ConstCopyAssign>> p2{3, 4}; |
| p2 = p1; |
| assert(p2.first.v.val == 1); |
| assert(p2.second.v.val == 2); |
| } |
| |
| // The correct assignment operator of the underlying type is used |
| { |
| std::pair<TracedAssignment, TracedAssignment> t1{}; |
| const std::pair<AssignableFrom<TracedAssignment>, AssignableFrom<TracedAssignment>> t2{}; |
| t2 = t1; |
| assert(t2.first.v.constCopyAssign == 1); |
| assert(t2.second.v.constCopyAssign == 1); |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| // gcc cannot have mutable member in constant expression |
| #if !defined(TEST_COMPILER_GCC) |
| static_assert(test()); |
| #endif |
| return 0; |
| } |