src/third_party/libc++/trunk/test/utilities/memory/pointer.traits/pointer.traits.functions/pointer_to.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is dual licensed under the MIT and the University of Illinois Open
   6 // Source Licenses. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 // <memory>
  11
  12 // template <class Ptr>
  13 // struct pointer_traits
  14 // {
  15 //     static pointer pointer_to(<details>);
  16 //     ...
  17 // };
  18
  19 #include <memory>
  20 #include <cassert>
  21
  22 template <class T>
  23 struct A
  24 {
  25 private:
  26     struct nat {};
  27 public:
  28     typedef T element_type;
  29     element_type* t_;
  30
  31     A(element_type* t) : t_(t) {}
  32
  33     static A pointer_to(typename std::conditional<std::is_void<element_type>::value,
  34                                            nat, element_type>::type& et)
  35         {return A(&et);}
  36 };
  37
  38 int main()
  39 {
  40     {
  41         int i = 0;
  42         A<int> a = std::pointer_traits<A<int> >::pointer_to(i);
  43         assert(a.t_ == &i);
  44     }
  45     {
  46         (std::pointer_traits<A<void> >::element_type)0;
  47     }
  48 }