fusion/iterator/key_of.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_ITERATOR_KEY_OF_HPP
0009 #define BOOST_FUSION_ITERATOR_KEY_OF_HPP
0010
0011 #include <boost/fusion/support/config.hpp>
0012 #include <boost/fusion/support/tag_of.hpp>
0013
0014 namespace boost { namespace fusion
0015 {
0016     struct iterator_facade_tag;
0017
0018     namespace extension
0019     {
0020         template <typename>
0021         struct key_of_impl;
0022
0023         template <>
0024         struct key_of_impl<iterator_facade_tag>
0025         {
0026             template <typename It>
0027             struct apply
0028               : It::template key_of<It>
0029             {};
0030         };
0031     }
0032
0033     namespace result_of
0034     {
0035         template <typename It>
0036         struct key_of
0037           : extension::key_of_impl<typename traits::tag_of<It>::type>::
0038                 template apply<It>
0039         {};
0040     }
0041 }}
0042
0043 #endif