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 observer_ptr(nullptr_t) noexcept; 18 19 #include <experimental/memory> 20 #include <cassert> 21 #include <cstddef> 22 #include <type_traits> 23 24 template <class T> test_nullptr_ctor()25constexpr void test_nullptr_ctor() { 26 using Ptr = std::experimental::observer_ptr<T>; 27 Ptr ptr = nullptr; 28 assert(ptr.get() == nullptr); 29 static_assert(std::is_nothrow_constructible<Ptr, std::nullptr_t>::value); 30 } 31 32 struct Foo; 33 struct Bar { BarBar34 Bar(int) {} 35 }; 36 test()37constexpr bool test() { 38 test_nullptr_ctor<Foo>(); 39 test_nullptr_ctor<Bar>(); 40 test_nullptr_ctor<int>(); 41 test_nullptr_ctor<void>(); 42 43 return true; 44 } 45 main(int,char **)46int main(int, char**) { 47 test(); 48 static_assert(test()); 49 50 return 0; 51 } 52