iterator_range/detail/value_at_impl.hpp

0001 /*=============================================================================
0002     Copyright (c) 2007 Tobias Schwinger
0003
0004     Distributed under the Boost Software License, Version 1.0. (See accompanying
0005     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 ==============================================================================*/
0007
0008 #if !defined(BOOST_FUSION_ITERATOR_RANGE_VALUE_AT_IMPL_HPP_INCLUDED)
0009 #define BOOST_FUSION_ITERATOR_RANGE_VALUE_AT_IMPL_HPP_INCLUDED
0010
0011 #include <boost/fusion/support/config.hpp>
0012 #include <boost/fusion/iterator/advance.hpp>
0013 #include <boost/fusion/iterator/value_of.hpp>
0014
0015 namespace boost { namespace fusion
0016 {
0017     struct iterator_range_tag;
0018
0019     namespace extension
0020     {
0021         template <typename Tag>
0022         struct value_at_impl;
0023
0024         template <>
0025         struct value_at_impl<iterator_range_tag>
0026         {
0027             template <typename Seq, typename N>
0028             struct apply
0029             {
0030                 typedef typename Seq::begin_type begin_type;
0031                 typedef typename result_of::advance<begin_type,N>::type pos;
0032                 typedef typename result_of::value_of<pos>::type type;
0033             };
0034         };
0035     }
0036 }}
0037
0038 #endif
0039