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

   1 // Copyright (C) 2018-2019 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 Add
  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   Int res = std::accumulate(std::begin(i), std::end(i), Int{0});
  71   VERIFY( res.copies == 0 );
  72   VERIFY( !res.moved_from );
  73   for (const auto& r : i)
  74     VERIFY( !r.moved_from );
  75 }
  76
  77 void
  78 test02()
  79 {
  80   Int i[] = { 0, 1, 2, 3, 4 };
  81   Int res = std::accumulate(std::begin(i), std::end(i), Int{0}, Add{});
  82   VERIFY( res.copies == 0 );
  83   VERIFY( !res.moved_from );
  84   for (const auto& r : i)
  85     VERIFY( !r.moved_from );
  86 }
  87
  88 int
  89 main()
  90 {
  91   test01();
  92   test02();
  93 }