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 // constexpr const tuple& operator=(const tuple&) const;
12 //
13 // Constraints: (is_copy_assignable_v<const Types> && ...) is true.
14
15 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
16
17 // test constraints
18
19 #include <cassert>
20 #include <tuple>
21 #include <type_traits>
22
23 #include "test_macros.h"
24 #include "copy_move_types.h"
25
26 static_assert(!std::is_assignable_v<const std::tuple<int>&, const std::tuple<int>&>);
27 static_assert(std::is_assignable_v<const std::tuple<int&>&, const std::tuple<int&>&>);
28 static_assert(std::is_assignable_v<const std::tuple<int&, int&>&, const std::tuple<int&, int&>&>);
29 static_assert(!std::is_assignable_v<const std::tuple<int&, int>&, const std::tuple<int&, int>&>);
30 static_assert(std::is_assignable_v<const std::tuple<ConstCopyAssign>&, const std::tuple<ConstCopyAssign>&>);
31 static_assert(!std::is_assignable_v<const std::tuple<CopyAssign>&, const std::tuple<CopyAssign>&>);
32 static_assert(!std::is_assignable_v<const std::tuple<ConstMoveAssign>&, const std::tuple<ConstMoveAssign>&>);
33 static_assert(!std::is_assignable_v<const std::tuple<MoveAssign>&, const std::tuple<MoveAssign>&>);
34
test()35 constexpr bool test() {
36 // reference types
37 {
38 int i1 = 1;
39 int i2 = 2;
40 double d1 = 3.0;
41 double d2 = 5.0;
42 const std::tuple<int&, double&> t1{i1, d1};
43 const std::tuple<int&, double&> t2{i2, d2};
44 t2 = t1;
45 assert(std::get<0>(t2) == 1);
46 assert(std::get<1>(t2) == 3.0);
47 }
48
49 // user defined const copy assignment
50 {
51 const std::tuple<ConstCopyAssign> t1{1};
52 const std::tuple<ConstCopyAssign> t2{2};
53 t2 = t1;
54 assert(std::get<0>(t2).val == 1);
55 }
56
57 // make sure the right assignment operator of the type in the tuple is used
58 {
59 std::tuple<TracedAssignment, const TracedAssignment> t1{};
60 const std::tuple<TracedAssignment, const TracedAssignment> t2{};
61 t2 = t1;
62 assert(std::get<0>(t2).constCopyAssign == 1);
63 assert(std::get<1>(t2).constCopyAssign == 1);
64 }
65
66 return true;
67 }
68
main(int,char **)69 int main(int, char**) {
70 test();
71
72 // gcc cannot have mutable member in constant expression
73 #if !defined(TEST_COMPILER_GCC)
74 static_assert(test());
75 #endif
76 return 0;
77 }
78