1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // UNSUPPORTED: c++03, c++11, c++14 10 // REQUIRES: c++experimental 11 12 // <experimental/memory> 13 14 // observer_ptr 15 // 16 // template <class W> 17 // std::experimental::observer_ptr<W> make_observer(W* p) noexcept; 18 19 #include <experimental/memory> 20 #include <cassert> 21 #include <type_traits> 22 23 template <class T, class Object = T> test_make_observer()24void test_make_observer() { 25 using Ptr = std::experimental::observer_ptr<T>; 26 Object obj; 27 T* raw = &obj; 28 29 Ptr ptr = std::experimental::make_observer(raw); 30 assert(ptr.get() == raw); 31 static_assert(noexcept(std::experimental::make_observer(raw))); 32 static_assert(std::is_same<decltype(std::experimental::make_observer(raw)), Ptr>::value); 33 } 34 35 struct Bar {}; 36 test()37void test() { 38 test_make_observer<void, int>(); 39 test_make_observer<int>(); 40 test_make_observer<Bar>(); 41 } 42 main(int,char **)43int main(int, char**) { 44 // Note: this is not constexpr in the spec 45 test(); 46 47 return 0; 48 } 49