libstdc++-v3/testsuite/experimental/optional/observers/3.cc

   1 // { dg-do run { target c++14 } }
   2
   3 // Copyright (C) 2013-2024 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 value_type
  24 {
  25   int i;
  26 };
  27
  28 int main()
  29 {
  30   {
  31     std::experimental::optional<value_type> o { value_type { 51 } };
  32     VERIFY( o.value().i == 51 );
  33     VERIFY( o.value().i == (*o).i );
  34     VERIFY( &o.value().i == &(*o).i );
  35   }
  36
  37   {
  38     enum outcome_type { nothrow, caught, bad_catch };
  39
  40     outcome_type outcome {};
  41     std::experimental::optional<value_type> o = std::experimental::nullopt;
  42     bool called = false;
  43     auto const eat = [&called](int) { called = true; };
  44
  45     try
  46     {
  47       eat(o.value().i);
  48     }
  49     catch(std::experimental::bad_optional_access const&)
  50     { outcome = caught; }
  51     catch(...)
  52     { outcome = bad_catch; }
  53
  54     VERIFY( outcome == caught );
  55     VERIFY( !called );
  56   }
  57 }