gdb/unittests/optional/assignment/1.cc

   1 // Copyright (C) 2013-2018 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 namespace assign_1 {
  19
  20 struct exception {};
  21
  22 int counter = 0;
  23
  24 struct mixin_counter
  25 {
  26   mixin_counter() { ++counter; }
  27   mixin_counter(mixin_counter const&) { ++counter; }
  28   ~mixin_counter() { --counter; }
  29 };
  30
  31 struct value_type : private mixin_counter
  32 {
  33   enum state_type
  34   {
  35     zero,
  36     moved_from,
  37     throwing_construction,
  38     throwing_copy,
  39     throwing_copy_assignment,
  40     throwing_move,
  41     throwing_move_assignment,
  42     threw,
  43   };
  44
  45   value_type() = default;
  46
  47   explicit value_type(state_type state_)
  48   : state(state_)
  49   {
  50     throw_if(throwing_construction);
  51   }
  52
  53   value_type(value_type const& other)
  54   : state(other.state)
  55   {
  56     throw_if(throwing_copy);
  57   }
  58
  59   value_type&
  60   operator=(value_type const& other)
  61   {
  62     state = other.state;
  63     throw_if(throwing_copy_assignment);
  64     return *this;
  65   }
  66
  67   value_type(value_type&& other)
  68   : state(other.state)
  69   {
  70     other.state = moved_from;
  71     throw_if(throwing_move);
  72   }
  73
  74   value_type&
  75   operator=(value_type&& other)
  76   {
  77     state = other.state;
  78     other.state = moved_from;
  79     throw_if(throwing_move_assignment);
  80     return *this;
  81   }
  82
  83   void throw_if(state_type match)
  84   {
  85     if(state == match)
  86     {
  87       state = threw;
  88       throw exception {};
  89     }
  90   }
  91
  92   state_type state = zero;
  93 };
  94
  95 void test()
  96 {
  97   using O = gdb::optional<value_type>;
  98   using S = value_type::state_type;
  99   auto const make = [](S s = S::zero) { return O { gdb::in_place, s }; };
 100
 101   enum outcome_type { nothrow, caught, bad_catch };
 102
 103   // Check copy/move assignment for disengaged optional
 104
 105   // From disengaged optional
 106   {
 107     O o;
 108     VERIFY( !o );
 109     O p;
 110     o = p;
 111     VERIFY( !o );
 112     VERIFY( !p );
 113   }
 114
 115   {
 116     O o;
 117     VERIFY( !o );
 118     O p;
 119     o = std::move(p);
 120     VERIFY( !o );
 121     VERIFY( !p );
 122   }
 123
 124 #ifndef GDB_OPTIONAL
 125   {
 126     O o;
 127     VERIFY( !o );
 128     o = {};
 129     VERIFY( !o );
 130   }
 131 #endif
 132
 133   // From engaged optional
 134   {
 135     O o;
 136     VERIFY( !o );
 137     O p = make(S::throwing_copy_assignment);
 138     o = p;
 139     VERIFY( o && o->state == S::throwing_copy_assignment );
 140     VERIFY( p && p->state == S::throwing_copy_assignment );
 141   }
 142
 143   {
 144     O o;
 145     VERIFY( !o );
 146     O p = make(S::throwing_move_assignment);
 147     o = std::move(p);
 148     VERIFY( o && o->state == S::throwing_move_assignment );
 149     VERIFY( p && p->state == S::moved_from );
 150   }
 151
 152   {
 153     outcome_type outcome {};
 154     O o;
 155     VERIFY( !o );
 156     O p = make(S::throwing_copy);
 157
 158     try
 159     {
 160       o = p;
 161     }
 162     catch(exception const&)
 163     { outcome = caught; }
 164     catch(...)
 165     { outcome = bad_catch; }
 166
 167     VERIFY( outcome == caught );
 168     VERIFY( !o );
 169     VERIFY( p && p->state == S::throwing_copy );
 170   }
 171
 172   {
 173     outcome_type outcome {};
 174     O o;
 175     VERIFY( !o );
 176     O p = make(S::throwing_move);
 177
 178     try
 179     {
 180       o = std::move(p);
 181     }
 182     catch(exception const&)
 183     { outcome = caught; }
 184     catch(...)
 185     { outcome = bad_catch; }
 186
 187     VERIFY( outcome == caught );
 188     VERIFY( !o );
 189     VERIFY( p && p->state == S::moved_from );
 190   }
 191
 192   VERIFY( counter == 0 );
 193 }
 194
 195 } // namespace assign_1