3rdparty/boost/boost/fusion/container/deque/deque_iterator.hpp

   1 /*=============================================================================
   2     Copyright (c) 2005-2012 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/support/config.hpp>
  12 #include <boost/fusion/iterator/iterator_facade.hpp>
  13 #include <boost/fusion/container/deque/detail/keyed_element.hpp>
  14 #include <boost/mpl/int.hpp>
  15 #include <boost/mpl/minus.hpp>
  16 #include <boost/mpl/equal_to.hpp>
  17 #include <boost/mpl/identity.hpp>
  18 #include <boost/mpl/if.hpp>
  19 #include <boost/type_traits/is_const.hpp>
  20 #include <boost/type_traits/add_const.hpp>
  21 #include <boost/type_traits/add_reference.hpp>
  22
  23 namespace boost { namespace fusion {
  24
  25     struct bidirectional_traversal_tag;
  26
  27     template <typename Seq, int Pos>
  28     struct deque_iterator
  29         : iterator_facade<deque_iterator<Seq, Pos>, bidirectional_traversal_tag>
  30     {
  31         typedef Seq sequence;
  32         typedef mpl::int_<Pos> index;
  33
  34         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  35         deque_iterator(Seq& seq)
  36             : seq_(seq)
  37         {}
  38
  39         template<typename Iterator>
  40         struct value_of
  41             : detail::keyed_element_value_at<
  42             typename Iterator::sequence, typename Iterator::index>
  43         {};
  44
  45         template<typename Iterator>
  46         struct deref
  47         {
  48             typedef typename detail::keyed_element_value_at<
  49                 typename Iterator::sequence, typename Iterator::index>::type element_type;
  50
  51             typedef typename add_reference<
  52                 typename mpl::eval_if<
  53                 is_const<typename Iterator::sequence>,
  54                 add_const<element_type>,
  55                 mpl::identity<element_type> >::type>::type type;
  56
  57             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  58             static type
  59             call(Iterator const& it)
  60             {
  61                 return it.seq_.get(typename Iterator::index());
  62             }
  63         };
  64
  65         template <typename Iterator, typename N>
  66         struct advance
  67         {
  68             typedef typename Iterator::index index;
  69             typedef typename Iterator::sequence sequence;
  70             typedef deque_iterator<sequence, index::value + N::value> type;
  71
  72             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  73             static type
  74             call(Iterator const& i)
  75             {
  76                 return type(i.seq_);
  77             }
  78         };
  79
  80         template<typename Iterator>
  81         struct next
  82             : advance<Iterator, mpl::int_<1> >
  83         {};
  84
  85         template<typename Iterator>
  86         struct prior
  87             : advance<Iterator, mpl::int_<-1> >
  88         {};
  89
  90         template <typename I1, typename I2>
  91         struct distance : mpl::minus<typename I2::index, typename I1::index>
  92         {
  93             typedef typename
  94                 mpl::minus<
  95                     typename I2::index, typename I1::index
  96                 >::type
  97             type;
  98
  99             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
 100             static type
 101             call(I1 const&, I2 const&)
 102             {
 103                 return type();
 104             }
 105         };
 106
 107         template<typename I1, typename I2>
 108         struct equal_to
 109             : mpl::equal_to<typename I1::index, typename I2::index>
 110         {};
 111
 112         Seq& seq_;
 113
 114     private:
 115         // silence MSVC warning C4512: assignment operator could not be generated
 116         deque_iterator& operator= (deque_iterator const&);
 117     };
 118
 119 }}
 120
 121 #ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
 122 namespace std
 123 {
 124     template <typename Seq, int Pos>
 125     struct iterator_traits< ::boost::fusion::deque_iterator<Seq, Pos> >
 126     { };
 127 }
 128 #endif
 129
 130 #endif