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 private:
27   struct nat {};
28 
29 public:
30   typedef T element_type;
31   element_type* t_;
32 
AA33   A(element_type* t) : t_(t) {}
34 
pointer_toA35   static A pointer_to(typename std::conditional<std::is_void<element_type>::value, nat, element_type>::type& et) {
36     return A(&et);
37   }
38 };
39 
40 template <class Pointer>
test()41 void test() {
42   typename Pointer::element_type obj;
43   static_assert(std::is_same<Pointer, decltype(std::pointer_traits<Pointer>::pointer_to(obj))>::value, "");
44   Pointer p = std::pointer_traits<Pointer>::pointer_to(obj);
45   assert(p.t_ == &obj);
46 }
47 
main(int,char **)48 int main(int, char**) {
49   test<A<int> >();
50   test<A<long> >();
51   { (std::pointer_traits<A<void> >::element_type)0; }
52 
53   return 0;
54 }
55