gdb/unittests/optional/assignment/4.cc

   1 // Copyright (C) 2013-2023 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 namespace assign_4 {
  19
  20 struct exception {};
  21
  22 static 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 static void
  96 test ()
  97 {
  98   using O = gdb::optional<value_type>;
  99   using S = value_type::state_type;
 100   auto const make = [](S s = S::zero) { return value_type { s }; };
 101
 102   enum outcome_type { nothrow, caught, bad_catch };
 103
 104   // Check value assignment for engaged optional
 105
 106   {
 107     O o = make();
 108     value_type v = make(S::throwing_copy);
 109     o = v;
 110     VERIFY( o && o->state == S::throwing_copy);
 111   }
 112
 113   {
 114     O o = make();
 115     value_type v = make(S::throwing_move);
 116     o = std::move(v);
 117     VERIFY( o && o->state == S::throwing_move);
 118   }
 119
 120   {
 121     ATTRIBUTE_UNUSED outcome_type outcome {};
 122     O o = make();
 123     value_type v = make(S::throwing_copy_assignment);
 124
 125     try
 126     {
 127       o = v;
 128     }
 129     catch(exception const&)
 130     { outcome = caught; }
 131     catch(...)
 132     { outcome = bad_catch; }
 133
 134     VERIFY( o && o->state == S::threw );
 135   }
 136
 137   {
 138     ATTRIBUTE_UNUSED outcome_type outcome {};
 139     O o = make();
 140     value_type v = make(S::throwing_move_assignment);
 141
 142     try
 143     {
 144       o = std::move(v);
 145     }
 146     catch(exception const&)
 147     { outcome = caught; }
 148     catch(...)
 149     { outcome = bad_catch; }
 150
 151     VERIFY( o && o->state == S::threw );
 152   }
 153
 154   VERIFY( counter == 0 );
 155 }
 156
 157 } // namespace assign_4