libstdc++-v3/testsuite/23_containers/array/requirements/non_default_constructible.cc

   1 // { dg-options "-std=gnu++11" }
   2 // { dg-do compile }
   3
   4 // Copyright (C) 2012-2013 Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11 //
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING3.  If not see
  19 // <http://www.gnu.org/licenses/>.
  20
  21 #include <array>
  22 #include <typeindex>
  23 #include <typeinfo>
  24
  25 template < typename ...Types >
  26 union super_union;
  27
  28 template < >
  29 union super_union<>
  30 {
  31   static  auto optioned_types() -> std::array<std::type_index, 0>
  32   { return std::array<std::type_index, 0>{ {} }; }
  33 };
  34
  35 template < typename Head, typename ...Tail >
  36 union super_union<Head, Tail...>
  37 {
  38   static
  39   auto optioned_types() -> std::array<std::type_index, 1 + sizeof...(Tail)>
  40   {
  41     using std::type_index;
  42
  43     return { {type_index(typeid(Head)), type_index(typeid(Tail))...} };
  44   }
  45
  46   Head                  data;
  47   super_union<Tail...>  rest;
  48 };