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 reset(element_type* p = nullptr) noexcept;
18
19#include <experimental/memory>
20#include <type_traits>
21#include <cassert>
22
23template <class T, class Object = T>
24constexpr void test_reset() {
25 using Ptr = std::experimental::observer_ptr<T>;
26 Object obj1, obj2;
27
28 {
29 Ptr ptr(&obj1);
30 assert(ptr.get() == &obj1);
31 ptr.reset(&obj2);
32 assert(ptr.get() == &obj2);
33 static_assert(noexcept(ptr.reset(&obj2)));
34 static_assert(std::is_same<decltype(ptr.reset(&obj2)), void>::value);
35 }
36 {
37 Ptr ptr(&obj1);
38 assert(ptr.get() == &obj1);
39 ptr.reset();
40 assert(ptr.get() == nullptr);
41 static_assert(noexcept(ptr.reset()));
42 static_assert(std::is_same<decltype(ptr.reset()), void>::value);
43 }
44}
45
46struct Bar {};
47
48constexpr bool test() {
49 test_reset<Bar>();
50 test_reset<int>();
51 test_reset<void, int>();
52
53 return true;
54}
55
56int main(int, char**) {
57 test();
58 static_assert(test());
59
60 return 0;
61}
62

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