xref: /llvm-project/libcxx/test/std/experimental/memory/memory.observer.ptr/release.pass.cpp (revision 7a62bee611f1c451fa026c146b03a3a277a5a1dd)
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 element_type* release() noexcept;
18 
19 #include <experimental/memory>
20 #include <type_traits>
21 #include <cassert>
22 
23 template <class T, class Object = T>
test_release()24 constexpr void test_release() {
25   Object obj;
26   using Ptr = std::experimental::observer_ptr<T>;
27   Ptr ptr(&obj);
28   assert(ptr.get() == &obj);
29 
30   decltype(auto) r = ptr.release();
31   assert(r == &obj);
32   assert(ptr.get() == nullptr);
33 
34   static_assert(std::is_same<decltype(r), typename Ptr::element_type*>::value);
35   static_assert(noexcept(ptr.release()));
36 }
37 
38 struct Bar {};
39 
test()40 constexpr bool test() {
41   test_release<Bar>();
42   test_release<int>();
43   test_release<void, int>();
44 
45   return true;
46 }
47 
main(int,char **)48 int main(int, char**) {
49   test();
50   static_assert(test());
51 
52   return 0;
53 }
54