detail/cpp03/key_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_KEY_OF_IMPL_HPP
0009 #define BOOST_FUSION_CONTAINER_MAP_DETAIL_KEY_OF_IMPL_HPP
0010
0011 #include <boost/fusion/support/config.hpp>
0012 #include <boost/fusion/container/map/detail/cpp03/value_of_impl.hpp>
0013
0014 namespace boost { namespace fusion { namespace extension
0015 {
0016     template <typename>
0017     struct key_of_impl;
0018
0019     template <>
0020     struct key_of_impl<map_iterator_tag>
0021     {
0022         template <typename It>
0023         struct apply
0024         {
0025             typedef typename
0026                 value_of_impl<map_iterator_tag>::
0027                     template apply<It>::type::first_type
0028             type;
0029         };
0030     };
0031 }}}
0032
0033 #endif