libstdc++-v3/testsuite/20_util/to_address/1.cc

   1 // Copyright (C) 2017-2020 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-options "-std=gnu++2a" }
  19 // { dg-do run { target c++2a } }
  20
  21 #include <memory>
  22 #include <testsuite_hooks.h>
  23
  24 class P1
  25 {
  26 public:
  27   using element_type = int;
  28
  29   explicit P1(int* p)
  30   : p_(p) { }
  31
  32   int* operator->() const noexcept
  33   { return p_; }
  34
  35 private:
  36   int* p_;
  37 };
  38
  39 class P2
  40 {
  41 public:
  42   using element_type = int;
  43
  44   explicit P2(int* p)
  45   : p_(p) { }
  46
  47   P1 operator->() const noexcept
  48   { return p_; }
  49
  50 private:
  51   P1 p_;
  52 };
  53
  54 class P3
  55 {
  56 public:
  57   explicit P3(int* p)
  58   : p_(p) { }
  59
  60   int* get() const noexcept
  61   { return p_; }
  62
  63 private:
  64   int* p_;
  65 };
  66
  67 namespace std
  68 {
  69   template<>
  70     struct pointer_traits<::P3>
  71     {
  72       static int* to_address(const ::P3& p) noexcept
  73       { return p.get(); }
  74     };
  75 }
  76
  77 class P4
  78 {
  79 public:
  80   explicit P4(int* p)
  81   : p_(p) { }
  82
  83   int* operator->() const noexcept
  84   { return nullptr; }
  85
  86   int* get() const noexcept
  87   { return p_; }
  88
  89 private:
  90   int* p_;
  91 };
  92
  93 namespace std
  94 {
  95   template<>
  96     struct pointer_traits<::P4>
  97     {
  98       static int* to_address(const ::P4& p) noexcept
  99       { return p.get(); }
 100     };
 101 }
 102
 103 void test01()
 104 {
 105   int i = 0;
 106   int* p = &i;
 107   VERIFY( std::to_address(p) == &i );
 108 }
 109
 110 void test02()
 111 {
 112   int i = 0;
 113   P1 p(&i);
 114   VERIFY( std::to_address(p) == &i );
 115 }
 116
 117 void test03()
 118 {
 119   int i = 0;
 120   P2 p(&i);
 121   VERIFY( std::to_address(p) == &i );
 122 }
 123
 124 void test04()
 125 {
 126   int i = 0;
 127   P3 p(&i);
 128   VERIFY( std::to_address(p) == &i );
 129 }
 130
 131 void test05()
 132 {
 133   int i = 0;
 134   P4 p(&i);
 135   VERIFY( std::to_address(p) == &i );
 136 }
 137
 138 int main()
 139 {
 140   test01();
 141   test02();
 142   test03();
 143   test04();
 144   test05();
 145   return 0;
 146 }