boost/fusion/view/iterator_range/detail/is_segmented_impl.hpp

   1 /*=============================================================================
   2     Copyright (c) 2011 Eric Niebler
   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(BOOST_FUSION_ITERATOR_RANGE_IS_SEGMENTED_HPP_INCLUDED)
   8 #define BOOST_FUSION_ITERATOR_RANGE_IS_SEGMENTED_HPP_INCLUDED
   9
  10 #include <boost/mpl/assert.hpp>
  11 #include <boost/mpl/bool.hpp>
  12
  13 namespace boost { namespace fusion
  14 {
  15     struct iterator_range_tag;
  16
  17     template <typename Context>
  18     struct segmented_iterator;
  19
  20     namespace extension
  21     {
  22         template <typename Tag>
  23         struct is_segmented_impl;
  24
  25         // An iterator_range of segmented_iterators is segmented
  26         template <>
  27         struct is_segmented_impl<iterator_range_tag>
  28         {
  29         private:
  30             template <typename Iterator>
  31             struct is_segmented_iterator
  32               : mpl::false_
  33             {};
  34
  35             template <typename Iterator>
  36             struct is_segmented_iterator<Iterator &>
  37               : is_segmented_iterator<Iterator>
  38             {};
  39
  40             template <typename Iterator>
  41             struct is_segmented_iterator<Iterator const>
  42               : is_segmented_iterator<Iterator>
  43             {};
  44
  45             template <typename Context>
  46             struct is_segmented_iterator<segmented_iterator<Context> >
  47               : mpl::true_
  48             {};
  49
  50         public:
  51             template <typename Sequence>
  52             struct apply
  53               : is_segmented_iterator<typename Sequence::begin_type>
  54             {
  55                 BOOST_MPL_ASSERT_RELATION(
  56                     is_segmented_iterator<typename Sequence::begin_type>::value
  57                   , ==
  58                   , is_segmented_iterator<typename Sequence::end_type>::value);
  59             };
  60         };
  61     }
  62 }}
  63
  64 #endif
  65
  66