boost/fusion/container/list/detail/build_cons.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2006 Joel de Guzman
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 ==============================================================================*/
   7 #if !defined(FUSION_BUILD_CONS_09232005_1222)
   8 #define FUSION_BUILD_CONS_09232005_1222
   9
  10 #include <boost/fusion/container/list/cons.hpp>
  11 #include <boost/fusion/iterator/equal_to.hpp>
  12 #include <boost/fusion/iterator/next.hpp>
  13 #include <boost/fusion/iterator/value_of.hpp>
  14 #include <boost/fusion/iterator/deref.hpp>
  15
  16 namespace boost { namespace fusion { namespace detail
  17 {
  18     template <
  19         typename First
  20       , typename Last
  21       , bool is_empty = result_of::equal_to<First, Last>::value>
  22     struct build_cons;
  23
  24     template <typename First, typename Last>
  25     struct build_cons<First, Last, true>
  26     {
  27         typedef nil type;
  28
  29         static nil
  30         call(First const&, Last const&)
  31         {
  32             return nil();
  33         }
  34     };
  35
  36     template <typename First, typename Last>
  37     struct build_cons<First, Last, false>
  38     {
  39         typedef
  40             build_cons<typename result_of::next<First>::type, Last>
  41         next_build_cons;
  42
  43         typedef cons<
  44             typename result_of::value_of<First>::type
  45           , typename next_build_cons::type>
  46         type;
  47
  48         static type
  49         call(First const& f, Last const& l)
  50         {
  51             return type(*f, next_build_cons::call(fusion::next(f), l));
  52         }
  53     };
  54
  55 }}}
  56
  57 #endif