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//===----------------------------------------------------------------------===//
//
// 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;
}
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