detail/cpp03/value_of_impl.hpp

0001 /*=============================================================================
0002     Copyright (c) 2009 Christopher Schmidt
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 #ifndef BOOST_FUSION_CONTAINER_MAP_DETAIL_VALUE_OF_IMPL_HPP
0009 #define BOOST_FUSION_CONTAINER_MAP_DETAIL_VALUE_OF_IMPL_HPP
0010
0011 #include <boost/fusion/support/config.hpp>
0012 #include <boost/fusion/sequence/intrinsic/value_at.hpp>
0013 #include <boost/type_traits/is_const.hpp>
0014
0015 namespace boost { namespace fusion { namespace extension
0016 {
0017     template <typename>
0018     struct value_of_impl;
0019
0020     template <>
0021     struct value_of_impl<map_iterator_tag>
0022     {
0023         template <typename It>
0024         struct apply
0025         {
0026             typedef typename
0027                 result_of::value_at<
0028                     typename mpl::if_<
0029                         is_const<typename It::seq_type>
0030                       , typename It::seq_type::storage_type const
0031                       , typename It::seq_type::storage_type
0032                     >::type
0033                   , typename It::index
0034                 >::type
0035             type;
0036         };
0037     };
0038 }}}
0039
0040 #endif