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 // <tuple>
10
11 // template <class... UTypes>
12 // constexpr const tuple& operator=(const tuple<UTypes...>& u) const;
13 //
14 // Constraints:
15 // - sizeof...(Types) equals sizeof...(UTypes) and
16 // - (is_assignable_v<const Types&, const UTypes&> && ...) is true.
17
18 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
19
20 #include <cassert>
21 #include <tuple>
22 #include <type_traits>
23
24 #include "test_macros.h"
25 #include "copy_move_types.h"
26
27 // test constraints
28
29 // sizeof...(Types) equals sizeof...(UTypes)
30 static_assert(std::is_assignable_v<const std::tuple<int&>&, const std::tuple<long&>&>);
31 static_assert(!std::is_assignable_v<const std::tuple<int&, int&>&, const std::tuple<long&>&>);
32 static_assert(!std::is_assignable_v<const std::tuple<int&>&, const std::tuple<long&, long&>&>);
33
34 // (is_assignable_v<const Types&, const UTypes&> && ...) is true
35 static_assert(std::is_assignable_v<const std::tuple<AssignableFrom<ConstCopyAssign>>&,
36 const std::tuple<ConstCopyAssign>&>);
37
38 static_assert(std::is_assignable_v<const std::tuple<AssignableFrom<ConstCopyAssign>, ConstCopyAssign>&,
39 const std::tuple<ConstCopyAssign, ConstCopyAssign>&>);
40
41 static_assert(!std::is_assignable_v<const std::tuple<AssignableFrom<ConstCopyAssign>, CopyAssign>&,
42 const std::tuple<ConstCopyAssign, CopyAssign>&>);
43
test()44 constexpr bool test() {
45 // reference types
46 {
47 int i1 = 1;
48 int i2 = 2;
49 long j1 = 3;
50 long j2 = 4;
51 const std::tuple<int&, int&> t1{i1, i2};
52 const std::tuple<long&, long&> t2{j1, j2};
53 t2 = t1;
54 assert(std::get<0>(t2) == 1);
55 assert(std::get<1>(t2) == 2);
56 }
57
58 // user defined const copy assignment
59 {
60 const std::tuple<ConstCopyAssign> t1{1};
61 const std::tuple<AssignableFrom<ConstCopyAssign>> t2{2};
62 t2 = t1;
63 assert(std::get<0>(t2).v.val == 1);
64 }
65
66 // make sure the right assignment operator of the type in the tuple is used
67 {
68 std::tuple<TracedAssignment> t1{};
69 const std::tuple<AssignableFrom<TracedAssignment>> t2{};
70 t2 = t1;
71 assert(std::get<0>(t2).v.constCopyAssign == 1);
72 }
73
74 return true;
75 }
76
main(int,char **)77 int main(int, char**) {
78 test();
79
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