xref: /llvm-project/libcxx/test/std/utilities/tuple/tuple.tuple/tuple.assign/convert_move.pass.cpp (revision 82c4701d4e7e6c3bb879a5e98d660a126025b87a)
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... Types> class tuple;
12 
13 // template <class... UTypes>
14 //   tuple& operator=(tuple<UTypes...>&& u);
15 
16 // UNSUPPORTED: c++03
17 
18 #include <tuple>
19 #include <string>
20 #include <memory>
21 #include <utility>
22 #include <cassert>
23 
24 #include "test_macros.h"
25 
26 struct B
27 {
28     int id_;
29 
30     explicit B(int i= 0) : id_(i) {}
31 
32     virtual ~B() {}
33 };
34 
35 struct D
36     : B
37 {
38     explicit D(int i) : B(i) {}
39 };
40 
41 struct E {
42   E() = default;
43   E& operator=(int) {
44       return *this;
45   }
46 };
47 
48 struct NonAssignable {
49   NonAssignable& operator=(NonAssignable const&) = delete;
50   NonAssignable& operator=(NonAssignable&&) = delete;
51 };
52 
53 int main(int, char**)
54 {
55     {
56         typedef std::tuple<long> T0;
57         typedef std::tuple<long long> T1;
58         T0 t0(2);
59         T1 t1;
60         t1 = std::move(t0);
61         assert(std::get<0>(t1) == 2);
62     }
63     {
64         typedef std::tuple<long, char> T0;
65         typedef std::tuple<long long, int> T1;
66         T0 t0(2, 'a');
67         T1 t1;
68         t1 = std::move(t0);
69         assert(std::get<0>(t1) == 2);
70         assert(std::get<1>(t1) == int('a'));
71     }
72     {
73         typedef std::tuple<long, char, D> T0;
74         typedef std::tuple<long long, int, B> T1;
75         T0 t0(2, 'a', D(3));
76         T1 t1;
77         t1 = std::move(t0);
78         assert(std::get<0>(t1) == 2);
79         assert(std::get<1>(t1) == int('a'));
80         assert(std::get<2>(t1).id_ == 3);
81     }
82     {
83         D d(3);
84         D d2(2);
85         typedef std::tuple<long, char, D&> T0;
86         typedef std::tuple<long long, int, B&> T1;
87         T0 t0(2, 'a', d2);
88         T1 t1(1, 'b', d);
89         t1 = std::move(t0);
90         assert(std::get<0>(t1) == 2);
91         assert(std::get<1>(t1) == int('a'));
92         assert(std::get<2>(t1).id_ == 2);
93     }
94     {
95         typedef std::tuple<long, char, std::unique_ptr<D>> T0;
96         typedef std::tuple<long long, int, std::unique_ptr<B>> T1;
97         T0 t0(2, 'a', std::unique_ptr<D>(new D(3)));
98         T1 t1;
99         t1 = std::move(t0);
100         assert(std::get<0>(t1) == 2);
101         assert(std::get<1>(t1) == int('a'));
102         assert(std::get<2>(t1)->id_ == 3);
103     }
104     {
105         // Test that tuple evaluates correctly applies an lvalue reference
106         // before evaluating is_assignable (i.e. 'is_assignable<int&, int&&>')
107         // instead of evaluating 'is_assignable<int&&, int&&>' which is false.
108         int x = 42;
109         int y = 43;
110         std::tuple<int&&, E> t(std::move(x), E{});
111         std::tuple<int&&, int> t2(std::move(y), 44);
112         t = std::move(t2);
113         assert(std::get<0>(t) == 43);
114         assert(&std::get<0>(t) == &x);
115     }
116     {
117       using T = std::tuple<int, NonAssignable>;
118       using U = std::tuple<NonAssignable, int>;
119       static_assert(!std::is_assignable<T, U&&>::value, "");
120       static_assert(!std::is_assignable<U, T&&>::value, "");
121     }
122 
123   return 0;
124 }
125