62 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 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