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 // <memory>
10 
11 // template <class Ptr>
12 // struct pointer_traits
13 // {
14 //     static pointer pointer_to(<details>);
15 //     ...
16 // };
17 
18 #include <memory>
19 #include <cassert>
20 #include <type_traits>
21 
22 #include "test_macros.h"
23 
24 template <class T>
25 struct A
26 {
27 private:
28     struct nat {};
29 public:
30     typedef T element_type;
31     element_type* t_;
32 
33     A(element_type* t) : t_(t) {}
34 
35     static A pointer_to(typename std::conditional<std::is_void<element_type>::value,
36                                            nat, element_type>::type& et)
37         {return A(&et);}
38 };
39 
40 int main(int, char**)
41 {
42     {
43         int i = 0;
44         static_assert((std::is_same<A<int>, decltype(std::pointer_traits<A<int> >::pointer_to(i))>::value), "");
45         A<int> a = std::pointer_traits<A<int> >::pointer_to(i);
46         assert(a.t_ == &i);
47     }
48     {
49         (std::pointer_traits<A<void> >::element_type)0;
50     }
51 
52   return 0;
53 }
54