boost/fusion/adapted/mpl/mpl_iterator.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_MPL_ITERATOR_05052005_0731)
   8 #define FUSION_MPL_ITERATOR_05052005_0731
   9
  10 #include <boost/fusion/support/detail/mpl_iterator_category.hpp>
  11 #include <boost/fusion/iterator/iterator_facade.hpp>
  12 #include <boost/type_traits/remove_const.hpp>
  13 #include <boost/mpl/deref.hpp>
  14 #include <boost/mpl/next.hpp>
  15 #include <boost/mpl/prior.hpp>
  16 #include <boost/mpl/advance.hpp>
  17 #include <boost/mpl/distance.hpp>
  18
  19 namespace boost { namespace fusion
  20 {
  21     template <typename Iterator_>
  22     struct mpl_iterator
  23         : iterator_facade<
  24             mpl_iterator<Iterator_>
  25           , typename detail::mpl_iterator_category<typename Iterator_::category>::type
  26         >
  27     {
  28         typedef typename remove_const<Iterator_>::type iterator_type;
  29
  30         template <typename Iterator>
  31         struct value_of : mpl::deref<typename Iterator::iterator_type> {};
  32
  33         template <typename Iterator>
  34         struct deref
  35         {
  36             typedef typename mpl::deref<
  37                 typename Iterator::iterator_type>::type
  38             type;
  39
  40             static type
  41             call(Iterator)
  42             {
  43                 return type();
  44             }
  45         };
  46
  47         template <typename Iterator>
  48         struct next
  49         {
  50             typedef mpl_iterator<
  51                 typename mpl::next<typename Iterator::iterator_type>::type>
  52             type;
  53
  54             static type
  55             call(Iterator)
  56             {
  57                 return type();
  58             }
  59         };
  60
  61         template <typename Iterator>
  62         struct prior
  63         {
  64             typedef mpl_iterator<
  65                 typename mpl::prior<typename Iterator::iterator_type>::type>
  66             type;
  67
  68             static type
  69             call(Iterator)
  70             {
  71                 return type();
  72             }
  73         };
  74
  75         template <typename Iterator, typename N>
  76         struct advance
  77         {
  78             typedef mpl_iterator<
  79                 typename mpl::advance<typename Iterator::iterator_type, N>::type>
  80             type;
  81
  82             static type
  83             call(Iterator const& /*i*/)
  84             {
  85                 return type();
  86             }
  87         };
  88
  89         template <typename I1, typename I2>
  90         struct distance :
  91             mpl::distance<
  92                 typename I1::iterator_type
  93               , typename I2::iterator_type>
  94         {
  95             typedef typename
  96                 mpl::distance<
  97                     typename I1::iterator_type
  98                   , typename I2::iterator_type
  99                 >::type
 100             type;
 101
 102             static type
 103             call(I1 const&, I2 const&)
 104             {
 105                 return type();
 106             }
 107         };
 108     };
 109 }}
 110
 111 #endif
 112
 113