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
24template <class T>
25struct A {
26private:
27 struct nat {};
28
29public:
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, nat, element_type>::type& et) {
36 return A(&et);
37 }
38};
39
40template <class Pointer>
41void 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
48int 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

source code of libcxx/test/std/utilities/memory/pointer.traits/pointer.traits.functions/pointer_to.pass.cpp