xref: /llvm-project/libcxx/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/move.pass.cpp (revision d5e26775d089d099d02b168de8ea52179b1b1f75)
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 // tuple(tuple&& u);
14 
15 // UNSUPPORTED: c++03
16 
17 #include <tuple>
18 #include <utility>
19 #include <cassert>
20 #include <memory>
21 
22 #include "test_macros.h"
23 #include "MoveOnly.h"
24 
25 struct ConstructsWithTupleLeaf
26 {
ConstructsWithTupleLeafConstructsWithTupleLeaf27     ConstructsWithTupleLeaf() {}
28 
ConstructsWithTupleLeafConstructsWithTupleLeaf29     ConstructsWithTupleLeaf(ConstructsWithTupleLeaf const &) { assert(false); }
ConstructsWithTupleLeafConstructsWithTupleLeaf30     ConstructsWithTupleLeaf(ConstructsWithTupleLeaf &&) {}
31 
32     template <class T>
ConstructsWithTupleLeafConstructsWithTupleLeaf33     ConstructsWithTupleLeaf(T) {
34         static_assert(!std::is_same<T, T>::value,
35                       "Constructor instantiated for type other than int");
36     }
37 };
38 
39 // move_only type which triggers the empty base optimization
40 struct move_only_ebo {
41   move_only_ebo() = default;
42   move_only_ebo(move_only_ebo&&) = default;
43 };
44 
45 // a move_only type which does not trigger the empty base optimization
46 struct move_only_large final {
move_only_largemove_only_large47   move_only_large() : value(42) {}
48   move_only_large(move_only_large&&) = default;
49   int value;
50 };
51 
52 template <class Elem>
test_sfinae()53 void test_sfinae() {
54     using Tup = std::tuple<Elem>;
55     using Alloc = std::allocator<int>;
56     using Tag = std::allocator_arg_t;
57     // special members
58     {
59         static_assert(std::is_default_constructible<Tup>::value, "");
60         static_assert(std::is_move_constructible<Tup>::value, "");
61         static_assert(!std::is_copy_constructible<Tup>::value, "");
62         static_assert(!std::is_constructible<Tup, Tup&>::value, "");
63     }
64     // args constructors
65     {
66         static_assert(std::is_constructible<Tup, Elem&&>::value, "");
67         static_assert(!std::is_constructible<Tup, Elem const&>::value, "");
68         static_assert(!std::is_constructible<Tup, Elem&>::value, "");
69     }
70     // uses-allocator special member constructors
71     {
72         static_assert(std::is_constructible<Tup, Tag, Alloc>::value, "");
73         static_assert(std::is_constructible<Tup, Tag, Alloc, Tup&&>::value, "");
74         static_assert(!std::is_constructible<Tup, Tag, Alloc, Tup const&>::value, "");
75         static_assert(!std::is_constructible<Tup, Tag, Alloc, Tup &>::value, "");
76     }
77     // uses-allocator args constructors
78     {
79         static_assert(std::is_constructible<Tup, Tag, Alloc, Elem&&>::value, "");
80         static_assert(!std::is_constructible<Tup, Tag, Alloc, Elem const&>::value, "");
81         static_assert(!std::is_constructible<Tup, Tag, Alloc, Elem &>::value, "");
82     }
83 }
84 
main(int,char **)85 int main(int, char**)
86 {
87     {
88         typedef std::tuple<> T;
89         T t0;
90         T t = std::move(t0);
91         ((void)t); // Prevent unused warning
92     }
93     {
94         typedef std::tuple<MoveOnly> T;
95         T t0(MoveOnly(0));
96         T t = std::move(t0);
97         assert(std::get<0>(t) == 0);
98     }
99     {
100         typedef std::tuple<MoveOnly, MoveOnly> T;
101         T t0(MoveOnly(0), MoveOnly(1));
102         T t = std::move(t0);
103         assert(std::get<0>(t) == 0);
104         assert(std::get<1>(t) == 1);
105     }
106     {
107         typedef std::tuple<MoveOnly, MoveOnly, MoveOnly> T;
108         T t0(MoveOnly(0), MoveOnly(1), MoveOnly(2));
109         T t = std::move(t0);
110         assert(std::get<0>(t) == 0);
111         assert(std::get<1>(t) == 1);
112         assert(std::get<2>(t) == 2);
113     }
114     // A bug in tuple caused __tuple_leaf to use its explicit converting constructor
115     //  as its move constructor. This tests that ConstructsWithTupleLeaf is not called
116     // (w/ __tuple_leaf)
117     {
118         typedef std::tuple<ConstructsWithTupleLeaf> d_t;
119         d_t d((ConstructsWithTupleLeaf()));
120         d_t d2(static_cast<d_t &&>(d));
121     }
122     {
123         test_sfinae<move_only_ebo>();
124         test_sfinae<move_only_large>();
125     }
126 
127   return 0;
128 }
129