51 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 observer_ptr() noexcept;18 19#include <experimental/memory>20#include <type_traits>21#include <cassert>22 23template <class T>24constexpr void test_default_ctor() {25 using Ptr = std::experimental::observer_ptr<T>;26 Ptr ptr;27 assert(ptr.get() == nullptr);28 static_assert(std::is_nothrow_default_constructible<Ptr>::value);29}30 31struct Foo;32struct Bar {33 Bar(int) {}34};35 36constexpr bool test() {37 test_default_ctor<Foo>();38 test_default_ctor<Bar>();39 test_default_ctor<int>();40 test_default_ctor<void>();41 42 return true;43}44 45int main(int, char**) {46 test();47 static_assert(test());48 49 return 0;50}51