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

   1 // { dg-do compile { target c++14 } }
   2
   3 // Copyright (C) 2013-2020 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 int main()
  24 {
  25   // [20.5.5] In-place construction
  26   static_assert( std::is_same<decltype(std::experimental::in_place), const std::experimental::in_place_t>(), "" );
  27   static_assert( std::is_empty<std::experimental::in_place_t>(), "" );
  28
  29   {
  30     constexpr std::experimental::optional<int> o { std::experimental::in_place };
  31     static_assert( o, "" );
  32     static_assert( *o == int {}, "" );
  33
  34     static_assert( !std::is_convertible<std::experimental::in_place_t, std::experimental::optional<int>>(), "" );
  35   }
  36
  37   {
  38     constexpr std::experimental::optional<int> o { std::experimental::in_place, 42 };
  39     static_assert( o, "" );
  40     static_assert( *o == 42, "" );
  41   }
  42 }