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 | // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20 |
10 | |
11 | // <utility> |
12 | |
13 | // template <class T1, class T2> struct pair |
14 | // constexpr const pair& operator=(const pair& p) const; |
15 | |
16 | #include <cassert> |
17 | #include <utility> |
18 | |
19 | #include "test_macros.h" |
20 | #include "copy_move_types.h" |
21 | |
22 | // Constraints: |
23 | // is_copy_assignable<const first_type> is true and |
24 | // is_copy_assignable<const second_type> is true. |
25 | |
26 | // clang-format off |
27 | static_assert(std::is_assignable_v<const std::pair<int&, int&>&, |
28 | const std::pair<int&, int&>&>); |
29 | static_assert(!std::is_assignable_v<const std::pair<int, int>&, |
30 | const std::pair<int, int>&>); |
31 | static_assert(!std::is_assignable_v<const std::pair<int, int&>&, |
32 | const std::pair<int, int&>&>); |
33 | static_assert(!std::is_assignable_v<const std::pair<int&, int>&, |
34 | const std::pair<int&, int>&>); |
35 | |
36 | static_assert(std::is_assignable_v<const std::pair<ConstCopyAssign, ConstCopyAssign>&, |
37 | const std::pair<ConstCopyAssign, ConstCopyAssign>&>); |
38 | static_assert(!std::is_assignable_v<const std::pair<CopyAssign, CopyAssign>&, |
39 | const std::pair<CopyAssign, CopyAssign>&>); |
40 | |
41 | // clang-format on |
42 | |
43 | constexpr bool test() { |
44 | // reference types |
45 | { |
46 | int i1 = 1; |
47 | int i2 = 2; |
48 | double d1 = 3.0; |
49 | double d2 = 5.0; |
50 | const std::pair<int&, double&> p1{i1, d1}; |
51 | const std::pair<int&, double&> p2{i2, d2}; |
52 | p2 = p1; |
53 | assert(p2.first == 1); |
54 | assert(p2.second == 3.0); |
55 | } |
56 | |
57 | // user defined const copy assignment |
58 | { |
59 | const std::pair<ConstCopyAssign, ConstCopyAssign> p1{1, 2}; |
60 | const std::pair<ConstCopyAssign, ConstCopyAssign> p2{3, 4}; |
61 | p2 = p1; |
62 | assert(p2.first.val == 1); |
63 | assert(p2.second.val == 2); |
64 | } |
65 | |
66 | // The correct assignment operator of the underlying type is used |
67 | { |
68 | std::pair<TracedAssignment, const TracedAssignment> t1{}; |
69 | const std::pair<TracedAssignment, const TracedAssignment> t2{}; |
70 | t2 = t1; |
71 | assert(t2.first.constCopyAssign == 1); |
72 | assert(t2.second.constCopyAssign == 1); |
73 | } |
74 | |
75 | return true; |
76 | } |
77 | |
78 | int main(int, char**) { |
79 | test(); |
80 | // gcc cannot have mutable member in constant expression |
81 | #if !defined(TEST_COMPILER_GCC) |
82 | static_assert(test()); |
83 | #endif |
84 | return 0; |
85 | } |
86 | |