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

   1 // Copyright (C) 2018-2023 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-do run { target c++20 } }
  19
  20 #include <numeric>
  21 #include <iterator>
  22 #include <testsuite_hooks.h>
  23
  24 struct Int
  25 {
  26   Int(int v) : val(v) { }
  27
  28   ~Int() = default;
  29
  30   Int(const Int& x) : val(x.val), copies(x.copies), moved_from(x.moved_from)
  31   { ++copies; }
  32
  33   Int(Int&& x) : val(x.val), copies(x.copies), moved_from(x.moved_from)
  34   { x.moved_from = true; }
  35
  36   Int& operator=(const Int& x)
  37   {
  38     val = x.val;
  39     copies = x.copies + 1;
  40     moved_from = x.moved_from;
  41     return *this;
  42   }
  43
  44   Int& operator=(Int&& x)
  45   {
  46     val = x.val;
  47     copies = x.copies;
  48     moved_from = x.moved_from;
  49     x.moved_from = true;
  50     return *this;
  51   }
  52
  53   int val = 0;
  54   int copies = 0;
  55   bool moved_from = false;
  56 };
  57
  58 Int operator-(Int x, Int y) { x.val -= y.val; return x; }
  59
  60 struct Subtract
  61 {
  62   Int operator()(Int x, Int y) const { x.val -= y.val; return x; }
  63 };
  64
  65 void
  66 test01()
  67 {
  68   Int i[] = { 0, 1, 2, 3, 4 };
  69   std::adjacent_difference(std::begin(i), std::end(i), std::begin(i));
  70   for (const auto& r : i)
  71   {
  72     VERIFY( r.copies == 2 );
  73     VERIFY( !r.moved_from );
  74   }
  75 }
  76
  77 void
  78 test02()
  79 {
  80   Int i[] = { 0, 1, 2, 3, 4 };
  81   std::adjacent_difference(std::begin(i), std::end(i), std::begin(i),
  82                            Subtract{});
  83   for (const auto& r : i)
  84   {
  85     VERIFY( r.copies == 2 );
  86     VERIFY( !r.moved_from );
  87   }
  88 }
  89
  90 void
  91 test03()
  92 {
  93   Int i[] = { 0, 1, 2, 3, 4 };
  94   std::adjacent_difference(std::make_move_iterator(std::begin(i)),
  95                            std::make_move_iterator(std::end(i)),
  96                            std::begin(i));
  97   for (const auto& r : i)
  98   {
  99     VERIFY( r.copies == 1 );
 100     VERIFY( !r.moved_from );
 101   }
 102 }
 103
 104 void
 105 test04()
 106 {
 107   Int i[] = { 0, 1, 2, 3, 4 };
 108   std::adjacent_difference(std::make_move_iterator(std::begin(i)),
 109                            std::make_move_iterator(std::end(i)),
 110                            std::begin(i), Subtract{});
 111   for (const auto& r : i)
 112   {
 113     VERIFY( r.copies == 1 );
 114     VERIFY( !r.moved_from );
 115   }
 116 }
 117
 118 int
 119 main()
 120 {
 121   test01();
 122   test02();
 123   test03();
 124   test04();
 125 }