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cd9b223a | 1 | // { dg-options "-std=gnu++14" } |
c98b0598 | 2 | |
818ab71a | 3 | // Copyright (C) 2013-2016 Free Software Foundation, Inc. |
c98b0598 JW |
4 | // |
5 | // This file is part of the GNU ISO C++ Library. This library is free | |
6 | // software; you can redistribute it and/or modify it under the | |
7 | // terms of the GNU General Public License as published by the | |
8 | // Free Software Foundation; either version 3, or (at your option) | |
9 | // any later version. | |
10 | ||
11 | // This library is distributed in the hope that it will be useful, | |
12 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | // GNU General Public License for more details. | |
15 | ||
16 | // You should have received a copy of the GNU General Public License along | |
17 | // with this library; see the file COPYING3. If not see | |
18 | // <http://www.gnu.org/licenses/>. | |
19 | ||
20 | // 20.2.3 exchange [utility.exchange] | |
21 | ||
22 | #include <utility> | |
23 | #include <type_traits> | |
24 | #include <testsuite_hooks.h> | |
25 | ||
26 | void | |
27 | test01() | |
28 | { | |
29 | const unsigned val = 4; | |
30 | int i = 1; | |
31 | auto prev = std::exchange(i, val); | |
32 | static_assert( std::is_same<decltype(prev), int>::value, "return type" ); | |
33 | VERIFY( i == 4 ); | |
34 | VERIFY( prev == 1 ); | |
35 | prev = std::exchange(i, 3); | |
36 | VERIFY( i == 3 ); | |
37 | VERIFY( prev == 4 ); | |
38 | } | |
39 | ||
40 | // Default construction from empty braces | |
41 | void | |
42 | test02() | |
43 | { | |
44 | bool test __attribute__((unused)) = true; | |
45 | ||
46 | struct DefaultConstructible | |
47 | { | |
48 | DefaultConstructible(int i = 0) : value(i) { } | |
49 | int value; | |
50 | }; | |
51 | ||
52 | DefaultConstructible x = 1; | |
53 | auto old = std::exchange(x, {}); | |
54 | VERIFY( x.value == 0 ); | |
55 | VERIFY( old.value == 1 ); | |
56 | } | |
57 | ||
37ea0d87 DN |
58 | int f(int) { return 0; } |
59 | ||
60 | double f(double) { return 0; } | |
61 | ||
c98b0598 JW |
62 | // Deduce type of overloaded function |
63 | void | |
64 | test03() | |
65 | { | |
66 | bool test __attribute__((unused)) = true; | |
67 | ||
68 | int (*fp)(int); | |
c98b0598 JW |
69 | std::exchange(fp, &f); |
70 | VERIFY( fp != nullptr ); | |
71 | } | |
72 | ||
73 | void test04() | |
74 | { | |
75 | struct From { }; | |
76 | struct To { | |
77 | int value = 0; | |
78 | To() = default; | |
79 | To(const To&) = default; | |
80 | To(const From&) = delete; | |
631e3e1b JW |
81 | To& operator=(const From&) { value = 1; return *this; } |
82 | To& operator=(From&&) { value = 2; return *this; } | |
c98b0598 JW |
83 | }; |
84 | ||
85 | To t; | |
86 | From f; | |
87 | ||
88 | auto prev = std::exchange(t, f); | |
89 | VERIFY( t.value == 1 ); | |
90 | VERIFY( prev.value == 0 ); | |
91 | ||
92 | prev = std::exchange(t, From{}); | |
93 | VERIFY( t.value == 2 ); | |
94 | VERIFY( prev.value == 1 ); | |
95 | } | |
96 | ||
97 | int | |
98 | main() | |
99 | { | |
100 | test01(); | |
101 | test02(); | |
102 | test03(); | |
103 | test04(); | |
104 | return 0; | |
105 | } |