ceph/src/boost/libs/fusion/include/boost/fusion/iterator/value_of.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 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_VALUE_OF_05052005_1126)
   8 #define FUSION_VALUE_OF_05052005_1126
   9
  10 #include <boost/fusion/support/config.hpp>
  11 #include <boost/fusion/support/iterator_base.hpp>
  12 #include <boost/fusion/support/tag_of.hpp>
  13
  14 namespace boost { namespace fusion
  15 {
  16     // Special tags:
  17     struct iterator_facade_tag; // iterator facade tag
  18     struct boost_array_iterator_tag; // boost::array iterator tag
  19     struct mpl_iterator_tag; // mpl sequence iterator tag
  20     struct std_pair_iterator_tag; // std::pair iterator tag
  21
  22     namespace extension
  23     {
  24         template <typename Tag>
  25         struct value_of_impl
  26         {
  27             template <typename Iterator>
  28             struct apply {};
  29         };
  30
  31         template <>
  32         struct value_of_impl<iterator_facade_tag>
  33         {
  34             template <typename Iterator>
  35             struct apply : Iterator::template value_of<Iterator> {};
  36         };
  37
  38         template <>
  39         struct value_of_impl<boost_array_iterator_tag>;
  40
  41         template <>
  42         struct value_of_impl<mpl_iterator_tag>;
  43
  44         template <>
  45         struct value_of_impl<std_pair_iterator_tag>;
  46     }
  47
  48     namespace result_of
  49     {
  50         template <typename Iterator>
  51         struct value_of
  52             : extension::value_of_impl<typename detail::tag_of<Iterator>::type>::
  53                 template apply<Iterator>
  54         {};
  55     }
  56 }}
  57
  58 #endif