libstdc++-v3/testsuite/experimental/optional/swap/1.cc

   1 // { dg-do run { target c++14 } }
   2
   3 // Copyright (C) 2013-2019 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20 #include <experimental/optional>
  21 #include <testsuite_hooks.h>
  22
  23 struct exception {};
  24
  25 int counter = 0;
  26
  27 struct mixin_counter
  28 {
  29   mixin_counter() { ++counter; }
  30   mixin_counter(mixin_counter const&) { ++counter; }
  31   ~mixin_counter() { --counter; }
  32 };
  33
  34 namespace ns
  35 {
  36
  37 struct value_type : private mixin_counter
  38 {
  39   explicit value_type(int state) : state(state) { }
  40   int state;
  41 };
  42
  43 int swaps = 0;
  44
  45 void
  46 swap(value_type& lhs, value_type& rhs)
  47 {
  48   ++swaps;
  49   using std::swap;
  50   swap(lhs.state, rhs.state);
  51 }
  52
  53 } // namespace ns
  54
  55 int main()
  56 {
  57   using O = std::experimental::optional<ns::value_type>;
  58
  59   VERIFY( ns::swaps == 0 );
  60
  61   {
  62     O o, p;
  63     swap(o, p);
  64     VERIFY( !o );
  65     VERIFY( !p );
  66   }
  67
  68   {
  69     O o { std::experimental::in_place, 45 }, p;
  70     swap(o, p);
  71     VERIFY( !o );
  72     VERIFY( p && p->state == 45 );
  73   }
  74
  75   {
  76     O o, p { std::experimental::in_place, 45 };
  77     swap(o, p);
  78     VERIFY( o && o->state == 45 );
  79     VERIFY( !p );
  80   }
  81
  82   {
  83     O o { std::experimental::in_place, 167 }, p { std::experimental::in_place, 999 };
  84     VERIFY( ns::swaps == 0 );
  85
  86     swap(o, p);
  87
  88     VERIFY( o && o->state == 999 );
  89     VERIFY( p && p->state == 167 );
  90     VERIFY( ns::swaps == 1 );
  91   }
  92
  93   VERIFY( counter == 0 );
  94 }