libstdc++-v3/testsuite/26_numerics/adjacent_difference/lwg2055.cc

   1 // Copyright (C) 2018-2022 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 <numeric>
  22 #include <iterator>
  23 #include <testsuite_hooks.h>
  24
  25 struct Int
  26 {
  27   Int(int v) : val(v) { }
  28
  29   ~Int() = default;
  30
  31   Int(const Int& x) : val(x.val), copies(x.copies), moved_from(x.moved_from)
  32   { ++copies; }
  33
  34   Int(Int&& x) : val(x.val), copies(x.copies), moved_from(x.moved_from)
  35   { x.moved_from = true; }
  36
  37   Int& operator=(const Int& x)
  38   {
  39     val = x.val;
  40     copies = x.copies + 1;
  41     moved_from = x.moved_from;
  42     return *this;
  43   }
  44
  45   Int& operator=(Int&& x)
  46   {
  47     val = x.val;
  48     copies = x.copies;
  49     moved_from = x.moved_from;
  50     x.moved_from = true;
  51     return *this;
  52   }
  53
  54   int val = 0;
  55   int copies = 0;
  56   bool moved_from = false;
  57 };
  58
  59 Int operator-(Int x, Int y) { x.val -= y.val; return x; }
  60
  61 struct Subtract
  62 {
  63   Int operator()(Int x, Int y) const { x.val -= y.val; return x; }
  64 };
  65
  66 void
  67 test01()
  68 {
  69   Int i[] = { 0, 1, 2, 3, 4 };
  70   std::adjacent_difference(std::begin(i), std::end(i), std::begin(i));
  71   for (const auto& r : i)
  72   {
  73     VERIFY( r.copies == 2 );
  74     VERIFY( !r.moved_from );
  75   }
  76 }
  77
  78 void
  79 test02()
  80 {
  81   Int i[] = { 0, 1, 2, 3, 4 };
  82   std::adjacent_difference(std::begin(i), std::end(i), std::begin(i),
  83                            Subtract{});
  84   for (const auto& r : i)
  85   {
  86     VERIFY( r.copies == 2 );
  87     VERIFY( !r.moved_from );
  88   }
  89 }
  90
  91 void
  92 test03()
  93 {
  94   Int i[] = { 0, 1, 2, 3, 4 };
  95   std::adjacent_difference(std::make_move_iterator(std::begin(i)),
  96                            std::make_move_iterator(std::end(i)),
  97                            std::begin(i));
  98   for (const auto& r : i)
  99   {
 100     VERIFY( r.copies == 1 );
 101     VERIFY( !r.moved_from );
 102   }
 103 }
 104
 105 void
 106 test04()
 107 {
 108   Int i[] = { 0, 1, 2, 3, 4 };
 109   std::adjacent_difference(std::make_move_iterator(std::begin(i)),
 110                            std::make_move_iterator(std::end(i)),
 111                            std::begin(i), Subtract{});
 112   for (const auto& r : i)
 113   {
 114     VERIFY( r.copies == 1 );
 115     VERIFY( !r.moved_from );
 116   }
 117 }
 118
 119 int
 120 main()
 121 {
 122   test01();
 123   test02();
 124   test03();
 125   test04();
 126 }