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 explicit operator bool() const noexcept;
18
19#include <experimental/memory>
20#include <type_traits>
21#include <cassert>
22
23template <class T, class Object = T>
24constexpr void test_operator_bool() {
25 using Ptr = std::experimental::observer_ptr<T>;
26 Object obj;
27
28 {
29 Ptr const ptr(&obj);
30 bool b = static_cast<bool>(ptr);
31 assert(b);
32
33 static_assert(noexcept(static_cast<bool>(ptr)));
34 }
35
36 {
37 Ptr const ptr(nullptr);
38 bool b = static_cast<bool>(ptr);
39 assert(!b);
40 }
41
42 static_assert(!std::is_convertible<Ptr const, bool>::value);
43 static_assert(std::is_constructible<bool, Ptr const>::value);
44}
45
46struct Bar {};
47
48constexpr bool test() {
49 test_operator_bool<Bar>();
50 test_operator_bool<int>();
51 test_operator_bool<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/operator-bool.pass.cpp