80 lines · cpp
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-exception7//8//===----------------------------------------------------------------------===//9 10// UNSUPPORTED: c++03, c++11, c++1411// REQUIRES: c++experimental12 13// <experimental/memory>14 15// observer_ptr16//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