git.sesse.net Git - casparcg/blob - dependencies/boost/boost/fusion/container/deque/deque_iterator.hpp

   1 /*=============================================================================
   2     Copyright (c) 2005-2011 Joel de Guzman
   3     Copyright (c) 2005-2006 Dan Marsden
   4
   5     Distributed under the Boost Software License, Version 1.0. (See accompanying
   6     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 ==============================================================================*/
   8 #if !defined(BOOST_FUSION_DEQUE_ITERATOR_26112006_2154)
   9 #define BOOST_FUSION_DEQUE_ITERATOR_26112006_2154
  10
  11 #include <boost/fusion/iterator/iterator_facade.hpp>
  12 #include <boost/fusion/container/deque/detail/keyed_element.hpp>
  13 #include <boost/mpl/minus.hpp>
  14 #include <boost/mpl/equal_to.hpp>
  15 #include <boost/type_traits/is_const.hpp>
  16
  17 namespace boost { namespace fusion {
  18
  19     struct bidirectional_traversal_tag;
  20
  21     template<typename Seq, int Pos>
  22     struct deque_iterator
  23         : iterator_facade<deque_iterator<Seq, Pos>, bidirectional_traversal_tag>
  24     {
  25         typedef Seq sequence;
  26         typedef mpl::int_<Pos> index;
  27
  28         deque_iterator(Seq& seq)
  29             : seq_(seq)
  30         {}
  31
  32         template<typename Iterator>
  33         struct value_of
  34             : detail::keyed_element_value_at<
  35             typename Iterator::sequence, typename Iterator::index>
  36         {};
  37
  38         template<typename Iterator>
  39         struct deref
  40         {
  41             typedef typename detail::keyed_element_value_at<
  42                 typename Iterator::sequence, typename Iterator::index>::type element_type;
  43
  44             typedef typename add_reference<
  45                 typename mpl::eval_if<
  46                 is_const<typename Iterator::sequence>,
  47                 add_const<element_type>,
  48                 mpl::identity<element_type> >::type>::type type;
  49
  50             static type
  51             call(Iterator const& it)
  52             {
  53                 return it.seq_.get(typename Iterator::index());
  54             }
  55         };
  56
  57         template <typename Iterator, typename N>
  58         struct advance
  59         {
  60             typedef typename Iterator::index index;
  61             typedef typename Iterator::sequence sequence;
  62             typedef deque_iterator<sequence, index::value + N::value> type;
  63
  64             static type
  65             call(Iterator const& i)
  66             {
  67                 return type(i.seq_);
  68             }
  69         };
  70
  71         template<typename Iterator>
  72         struct next
  73             : advance<Iterator, mpl::int_<1> >
  74         {};
  75
  76         template<typename Iterator>
  77         struct prior
  78             : advance<Iterator, mpl::int_<-1> >
  79         {};
  80
  81         template <typename I1, typename I2>
  82         struct distance : mpl::minus<typename I2::index, typename I1::index>
  83         {
  84             typedef typename
  85                 mpl::minus<
  86                     typename I2::index, typename I1::index
  87                 >::type
  88             type;
  89
  90             static type
  91             call(I1 const&, I2 const&)
  92             {
  93                 return type();
  94             }
  95         };
  96
  97         template<typename I1, typename I2>
  98         struct equal_to
  99             : mpl::equal_to<typename I1::index, typename I2::index>
 100         {};
 101
 102         Seq& seq_;
 103
 104     private:
 105         // silence MSVC warning C4512: assignment operator could not be generated
 106         deque_iterator& operator= (deque_iterator const&);
 107     };
 108
 109 }}
 110
 111 #endif