ceph/src/boost/boost/fusion/support/category_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_CATEGORY_OF_07202005_0308)
   8 #define FUSION_CATEGORY_OF_07202005_0308
   9
  10 #include <boost/fusion/support/config.hpp>
  11 #include <boost/fusion/support/tag_of.hpp>
  12 #include <boost/type_traits/is_base_of.hpp>
  13
  14 namespace boost { namespace fusion
  15 {
  16     // Special tags:
  17     struct boost_tuple_tag; // boost::tuples::tuple tag
  18     struct boost_array_tag; // boost::array tag
  19     struct mpl_sequence_tag; // mpl sequence tag
  20     struct std_pair_tag; // std::pair tag
  21
  22     struct incrementable_traversal_tag {};
  23
  24     struct single_pass_traversal_tag
  25         : incrementable_traversal_tag {};
  26
  27     struct forward_traversal_tag
  28         : single_pass_traversal_tag {};
  29
  30     struct bidirectional_traversal_tag
  31         : forward_traversal_tag {};
  32
  33     struct random_access_traversal_tag
  34         : bidirectional_traversal_tag {};
  35
  36     struct associative_tag {};
  37
  38     struct unbounded_tag {};
  39
  40     namespace extension
  41     {
  42         template<typename Tag>
  43         struct category_of_impl
  44         {
  45             template<typename T>
  46             struct apply
  47             {
  48                 typedef typename T::category type;
  49             };
  50         };
  51
  52         template <>
  53         struct category_of_impl<boost_tuple_tag>;
  54
  55         template <>
  56         struct category_of_impl<boost_array_tag>;
  57
  58         template <>
  59         struct category_of_impl<mpl_sequence_tag>;
  60
  61         template <>
  62         struct category_of_impl<std_pair_tag>;
  63     }
  64
  65     namespace traits
  66     {
  67         template <typename T>
  68         struct category_of
  69             : extension::category_of_impl<typename fusion::detail::tag_of<T>::type>::
  70                 template apply<T>
  71         {};
  72
  73         template <typename T>
  74         struct is_associative
  75             : is_base_of<
  76                 associative_tag
  77               , typename category_of<T>::type>
  78         {};
  79
  80         template <typename T>
  81         struct is_incrementable
  82             : is_base_of<
  83                 incrementable_traversal_tag
  84               , typename category_of<T>::type>
  85         {};
  86
  87         template <typename T>
  88         struct is_single_pass
  89             : is_base_of<
  90                 single_pass_traversal_tag
  91               , typename category_of<T>::type>
  92         {};
  93
  94         template <typename T>
  95         struct is_forward
  96             : is_base_of<
  97                 forward_traversal_tag
  98               , typename category_of<T>::type>
  99         {};
 100
 101         template <typename T>
 102         struct is_bidirectional
 103             : is_base_of<
 104                 bidirectional_traversal_tag
 105               , typename category_of<T>::type>
 106         {};
 107
 108         template <typename T>
 109         struct is_random_access
 110             : is_base_of<
 111                 random_access_traversal_tag
 112               , typename category_of<T>::type>
 113         {};
 114
 115         template <typename T>
 116         struct is_unbounded
 117             : is_base_of<
 118                 unbounded_tag
 119               , typename category_of<T>::type>
 120         {};
 121     }
 122 }}
 123
 124 #endif