libstdc++-v3/include/ext/pb_ds/detail/typelist/typelist_append.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006 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 terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 2, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License
  17 // along with this library; see the file COPYING.  If not, write to
  18 // the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
  19 // MA 02111-1307, USA.
  20
  21 // As a special exception, you may use this file as part of a free
  22 // software library without restriction.  Specifically, if other files
  23 // instantiate templates or use macros or inline functions from this
  24 // file, or you compile this file and link it with other files to
  25 // produce an executable, this file does not by itself cause the
  26 // resulting executable to be covered by the GNU General Public
  27 // License.  This exception does not however invalidate any other
  28 // reasons why the executable file might be covered by the GNU General
  29 // Public License.
  30
  31 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  32
  33 // Permission to use, copy, modify, sell, and distribute this software
  34 // is hereby granted without fee, provided that the above copyright
  35 // notice appears in all copies, and that both that copyright notice
  36 // and this permission notice appear in supporting documentation. None
  37 // of the above authors, nor IBM Haifa Research Laboratories, make any
  38 // representation about the suitability of this software for any
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  40 // warranty.
  41
  42 /**
  43  * @file typelist_append.hpp
  44  * Contains typelist_chain utilities.
  45  * Typelists are an idea by Andrei Alexandrescu.
  46  */
  47
  48 #ifndef PB_DS_TYPELIST_APPEND_HPP
  49 #define PB_DS_TYPELIST_APPEND_HPP
  50
  51 #include <ext/pb_ds/detail/type_utils.hpp>
  52
  53 namespace detail
  54 {
  55   template<typename Typelist_Chain0, class Typelist_Chain1>
  56   struct typelist_append_;
  57
  58   template<typename Hd, typename Tl, class Typelist_Chain1>
  59   struct typelist_append_<typelist_chain<Hd, Tl>, Typelist_Chain1>
  60   {
  61     typedef typelist_chain<Hd, typename typelist_append_<Tl, Typelist_Chain1>::type> type;
  62   };
  63
  64   template<typename Typelist_Chain1>
  65   struct typelist_append_< null_type, Typelist_Chain1>
  66   {
  67     typedef Typelist_Chain1 type;
  68   };
  69
  70   template<typename Typelist_Chain0>
  71   struct typelist_append_<Typelist_Chain0, null_type>
  72   {
  73     typedef Typelist_Chain0 type;
  74   };
  75
  76   template<>
  77   struct typelist_append_<null_type, null_type>
  78   {
  79     typedef null_type type;
  80   };
  81 } // namespace detail
  82
  83 #endif // #ifndef PB_DS_TYPELIST_APPEND_HPP
  84