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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
//
//===----------------------------------------------------------------------===//
// <tuple>
// template<class U1, class U2>
// constexpr const tuple& operator=(pair<U1, U2>&& u) const;
//
// - sizeof...(Types) is 2,
// - is_assignable_v<const T1&, U1> is true, and
// - is_assignable_v<const T2&, U2> is true
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
#include <cassert>
#include <tuple>
#include <type_traits>
#include <utility>
#include "test_macros.h"
#include "copy_move_types.h"
// test constraints
// sizeof...(Types) != 2,
static_assert(std::is_assignable_v<const std::tuple<int&, int&>&, std::pair<int&, int&>&&>);
static_assert(!std::is_assignable_v<const std::tuple<int&>&, std::pair<int&, int&>&&>);
static_assert(!std::is_assignable_v<const std::tuple<int&, int&, int&>&, std::pair<int&, int&>&&>);
static_assert(std::is_assignable_v<const std::tuple<AssignableFrom<ConstMoveAssign>, ConstMoveAssign>&,
std::pair<ConstMoveAssign, ConstMoveAssign>&&>);
// is_assignable_v<const T1&, U1> is false
static_assert(!std::is_assignable_v<const std::tuple<AssignableFrom<MoveAssign>, ConstMoveAssign>&,
std::pair<MoveAssign, ConstMoveAssign>&&>);
// is_assignable_v<const T2&, U2> is false
static_assert(!std::is_assignable_v<const std::tuple<AssignableFrom<ConstMoveAssign>, AssignableFrom<MoveAssign>>&,
std::tuple<ConstMoveAssign, MoveAssign>&&>);
constexpr bool test() {
// reference types
{
int i1 = 1;
int i2 = 2;
long j1 = 3;
long j2 = 4;
std::pair<int&, int&> t1{i1, i2};
const std::tuple<long&, long&> t2{j1, j2};
t2 = std::move(t1);
assert(std::get<0>(t2) == 1);
assert(std::get<1>(t2) == 2);
}
// user defined const copy assignment
{
std::pair<ConstMoveAssign, ConstMoveAssign> t1{1, 2};
const std::tuple<AssignableFrom<ConstMoveAssign>, ConstMoveAssign> t2{3, 4};
t2 = std::move(t1);
assert(std::get<0>(t2).v.val == 1);
assert(std::get<1>(t2).val == 2);
}
// make sure the right assignment operator of the type in the tuple is used
{
std::pair<TracedAssignment, TracedAssignment> t1{};
const std::tuple<AssignableFrom<TracedAssignment>, AssignableFrom<TracedAssignment>> t2{};
t2 = std::move(t1);
assert(std::get<0>(t2).v.constMoveAssign == 1);
assert(std::get<1>(t2).v.constMoveAssign == 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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