libstdc++-v3/testsuite/experimental/optional/in_place.cc

   1 // { dg-do run { target c++14 } }
   2
   3 // Copyright (C) 2013-2017 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 #include <vector>
  24
  25 int main()
  26 {
  27   // [20.5.5] In-place construction
  28   static_assert( std::is_same<decltype(std::experimental::in_place), const std::experimental::in_place_t>(), "" );
  29   static_assert( std::is_empty<std::experimental::in_place_t>(), "" );
  30
  31   {
  32     std::experimental::optional<int> o { std::experimental::in_place };
  33     VERIFY( o );
  34     VERIFY( *o == int() );
  35
  36     static_assert( !std::is_convertible<std::experimental::in_place_t, std::experimental::optional<int>>(), "" );
  37   }
  38
  39   {
  40     std::experimental::optional<int> o { std::experimental::in_place, 42 };
  41     VERIFY( o );
  42     VERIFY( *o == 42 );
  43   }
  44
  45   {
  46     std::experimental::optional<std::vector<int>> o { std::experimental::in_place, 18, 4 };
  47     VERIFY( o );
  48     VERIFY( o->size() == 18 );
  49     VERIFY( (*o)[17] == 4 );
  50   }
  51
  52   {
  53     std::experimental::optional<std::vector<int>> o { std::experimental::in_place, { 18, 4 } };
  54     VERIFY( o );
  55     VERIFY( o->size() == 2 );
  56     VERIFY( (*o)[0] == 18 );
  57   }
  58
  59   {
  60     std::experimental::optional<std::vector<int>> o { std::experimental::in_place, { 18, 4 }, std::allocator<int> {} };
  61     VERIFY( o );
  62     VERIFY( o->size() == 2 );
  63     VERIFY( (*o)[0] == 18 );
  64   }
  65 }