1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// <utility>
10
11// template <class T1, class T2> struct pair
12
13// template<class U, class V> pair& operator=(const pair<U, V>& p);
14
15#include <utility>
16#include <cassert>
17
18#include "test_macros.h"
19#if TEST_STD_VER >= 11
20#include "archetypes.h"
21#endif
22
23struct CopyAssignableInt {
24 CopyAssignableInt& operator=(int&) { return *this; }
25};
26
27struct Unrelated {};
28
29TEST_CONSTEXPR_CXX20 bool test() {
30 {
31 typedef std::pair<int, short> P1;
32 typedef std::pair<double, long> P2;
33 P1 p1(3, static_cast<short>(4));
34 P2 p2;
35 p2 = p1;
36 assert(p2.first == 3);
37 assert(p2.second == 4);
38 }
39#if TEST_STD_VER >= 20
40 {
41 using C = ConstexprTestTypes::TestType;
42 using P = std::pair<int, C>;
43 using T = std::pair<long, C>;
44 const T t(42, -42);
45 P p(101, 101);
46 p = t;
47 assert(p.first == 42);
48 assert(p.second.value == -42);
49 }
50#elif TEST_STD_VER >= 11
51 {
52 using C = TestTypes::TestType;
53 using P = std::pair<int, C>;
54 using T = std::pair<long, C>;
55 const T t(42, -42);
56 P p(101, 101);
57 C::reset_constructors();
58 p = t;
59 assert(C::constructed == 0);
60 assert(C::assigned == 1);
61 assert(C::copy_assigned == 1);
62 assert(C::move_assigned == 0);
63 assert(p.first == 42);
64 assert(p.second.value == -42);
65 }
66 { // test const requirement
67 using T = std::pair<CopyAssignableInt, CopyAssignableInt>;
68 using P = std::pair<int, int>;
69 static_assert(!std::is_assignable<T&, P const>::value, "");
70 }
71 {
72 using T = std::pair<int, Unrelated>;
73 using P = std::pair<Unrelated, int>;
74 static_assert(!std::is_assignable<T&, P&>::value, "");
75 static_assert(!std::is_assignable<P&, T&>::value, "");
76 }
77#endif
78#if TEST_STD_VER >= 11 || defined(_LIBCPP_VERSION) // valid in C++11, provided in C++03 with libc++ as an extension
79 {
80 int i = 0, j = 0;
81 std::pair<int&, int&> p(i, j);
82 const std::pair<const int, const int> from(11, 12);
83 p = from;
84 assert(i == 11);
85 assert(j == 12);
86 }
87#endif
88 return true;
89}
90
91int main(int, char**) {
92 test();
93#if TEST_STD_VER >= 20
94 static_assert(test());
95#endif
96
97 return 0;
98}
99

source code of libcxx/test/std/utilities/utility/pairs/pairs.pair/assign_const_pair_U_V.pass.cpp