| 1 | //===----------------------------------------------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20 |
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| 10 | |
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| 11 | // <utility> |
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| 12 | |
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| 13 | // template <class T1, class T2> struct pair |
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| 14 | // template<class U1, class U2> constexpr |
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| 15 | // const pair& operator=(const pair<U1, U2>& p) const; |
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| 16 | |
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| 17 | #include <cassert> |
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| 18 | #include <utility> |
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| 19 | |
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| 20 | #include "test_macros.h" |
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| 21 | #include "copy_move_types.h" |
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| 22 | |
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| 23 | // Constraints: |
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| 24 | // is_assignable_v<const first_type&, const U1&> is true, and |
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| 25 | // is_assignable_v<const second_type&, const U2&> is true. |
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| 26 | |
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| 27 | // clang-format off |
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| 28 | static_assert( std::is_assignable_v<const std::pair<int&, int&>&, |
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| 29 | const std::pair<long&, long&>&>); |
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| 30 | static_assert(!std::is_assignable_v<const std::pair<int, int>&, |
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| 31 | const std::pair<long, long>&>); |
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| 32 | static_assert(!std::is_assignable_v<const std::pair<int, int&>&, |
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| 33 | const std::pair<long, long&>&>); |
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| 34 | static_assert(!std::is_assignable_v<const std::pair<int&, int>&, |
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| 35 | const std::pair<long&, long>&>); |
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| 36 | |
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| 37 | static_assert(std::is_assignable_v< |
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| 38 | const std::pair<AssignableFrom<ConstCopyAssign>, AssignableFrom<ConstCopyAssign>>&, |
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| 39 | const std::pair<ConstCopyAssign, ConstCopyAssign>&>); |
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| 40 | |
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| 41 | static_assert(!std::is_assignable_v< |
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| 42 | const std::pair<AssignableFrom<CopyAssign>, AssignableFrom<CopyAssign>>&, |
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| 43 | const std::pair<CopyAssign, CopyAssign>&>); |
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| 44 | // clang-format on |
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| 45 | |
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| 46 | constexpr bool test() { |
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| 47 | // reference types |
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| 48 | { |
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| 49 | int i1 = 1; |
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| 50 | int i2 = 2; |
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| 51 | long j1 = 3; |
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| 52 | long j2 = 4; |
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| 53 | const std::pair<int&, int&> p1{i1, i2}; |
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| 54 | const std::pair<long&, long&> p2{j1, j2}; |
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| 55 | p2 = p1; |
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| 56 | assert(p2.first == 1); |
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| 57 | assert(p2.second == 2); |
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| 58 | } |
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| 59 | |
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| 60 | // user defined const copy assignment |
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| 61 | { |
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| 62 | const std::pair<ConstCopyAssign, ConstCopyAssign> p1{1, 2}; |
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| 63 | const std::pair<AssignableFrom<ConstCopyAssign>, AssignableFrom<ConstCopyAssign>> p2{3, 4}; |
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| 64 | p2 = p1; |
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| 65 | assert(p2.first.v.val == 1); |
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| 66 | assert(p2.second.v.val == 2); |
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| 67 | } |
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| 68 | |
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| 69 | // The correct assignment operator of the underlying type is used |
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| 70 | { |
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| 71 | std::pair<TracedAssignment, TracedAssignment> t1{}; |
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| 72 | const std::pair<AssignableFrom<TracedAssignment>, AssignableFrom<TracedAssignment>> t2{}; |
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| 73 | t2 = t1; |
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| 74 | assert(t2.first.v.constCopyAssign == 1); |
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| 75 | assert(t2.second.v.constCopyAssign == 1); |
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| 76 | } |
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| 77 | |
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| 78 | return true; |
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| 79 | } |
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| 80 | |
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| 81 | int main(int, char**) { |
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| 82 | test(); |
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| 83 | // gcc cannot have mutable member in constant expression |
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| 84 | #if !defined(TEST_COMPILER_GCC) |
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| 85 | static_assert(test()); |
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| 86 | #endif |
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| 87 | return 0; |
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| 88 | } |
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| 89 | |
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