1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10// UNSUPPORTED: c++03, c++11, c++14
11// REQUIRES: c++experimental
12
13// <experimental/memory>
14
15// observer_ptr
16//
17// constexpr void swap(observer_ptr& other) noexcept;
18//
19// template <class W>
20// void swap(observer_ptr<W>& lhs, observer_ptr<W>& rhs) noexcept;
21
22#include <experimental/memory>
23#include <type_traits>
24#include <cassert>
25
26template <class T, class Object = T>
27constexpr void test_swap() {
28 using Ptr = std::experimental::observer_ptr<T>;
29 Object obj1, obj2;
30
31 {
32 Ptr ptr1(&obj1);
33 Ptr ptr2(&obj2);
34
35 assert(ptr1.get() == &obj1);
36 assert(ptr2.get() == &obj2);
37
38 ptr1.swap(ptr2);
39
40 assert(ptr1.get() == &obj2);
41 assert(ptr2.get() == &obj1);
42
43 static_assert(noexcept(ptr1.swap(ptr2)));
44 static_assert(std::is_same<decltype(ptr1.swap(ptr2)), void>::value);
45 }
46
47 {
48 Ptr ptr1(&obj1);
49 Ptr ptr2(&obj2);
50
51 assert(ptr1.get() == &obj1);
52 assert(ptr2.get() == &obj2);
53
54 std::experimental::swap(ptr1, ptr2);
55
56 assert(ptr1.get() == &obj2);
57 assert(ptr2.get() == &obj1);
58
59 static_assert(noexcept(std::experimental::swap(ptr1, ptr2)));
60 static_assert(std::is_same<decltype(std::experimental::swap(ptr1, ptr2)), void>::value);
61 }
62}
63
64struct Bar {};
65
66constexpr bool test() {
67 test_swap<Bar>();
68 test_swap<int>();
69 test_swap<void, int>();
70
71 return true;
72}
73
74int main(int, char**) {
75 test();
76 static_assert(test());
77
78 return 0;
79}
80

source code of libcxx/test/std/experimental/memory/memory.observer.ptr/swap.pass.cpp