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 std::add_lvalue_reference_t<element_type> operator*() const; 18 // constexpr element_type* operator->() const noexcept; 19 20 #include <experimental/memory> 21 #include <type_traits> 22 #include <cassert> 23 24 template <class T, class Object = T> test_deref()25constexpr void test_deref() { 26 using Ptr = std::experimental::observer_ptr<T>; 27 Object obj; 28 29 { 30 Ptr const ptr(&obj); 31 T& r = *ptr; 32 assert(&r == &obj); 33 } 34 { 35 Ptr const ptr(&obj); 36 T* r = ptr.operator->(); 37 assert(r == &obj); 38 static_assert(noexcept(ptr.operator->())); 39 } 40 } 41 42 struct Bar {}; 43 struct Foo { 44 int member = 42; 45 }; 46 test()47constexpr bool test() { 48 test_deref<Bar>(); 49 test_deref<int>(); 50 51 { 52 Foo foo; 53 std::experimental::observer_ptr<Foo> ptr(&foo); 54 assert(&ptr->member == &foo.member); 55 } 56 57 return true; 58 } 59 main(int,char **)60int main(int, char**) { 61 test(); 62 static_assert(test()); 63 64 return 0; 65 } 66