ceph/src/boost/boost/fusion/adapted/boost_array/array_iterator.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 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_ARRAY_ITERATOR_26122005_2250)
   9 #define BOOST_FUSION_ARRAY_ITERATOR_26122005_2250
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <cstddef>
  13 #include <boost/config.hpp>
  14 #include <boost/mpl/int.hpp>
  15 #include <boost/mpl/assert.hpp>
  16 #include <boost/mpl/if.hpp>
  17 #include <boost/mpl/minus.hpp>
  18 #include <boost/type_traits/is_const.hpp>
  19 #include <boost/fusion/iterator/iterator_facade.hpp>
  20
  21 namespace boost { namespace fusion
  22 {
  23     struct random_access_traversal_tag;
  24
  25     template <typename Array, int Pos>
  26     struct array_iterator
  27         : iterator_facade<array_iterator<Array, Pos>, random_access_traversal_tag>
  28     {
  29         BOOST_MPL_ASSERT_RELATION(Pos, >=, 0);
  30         BOOST_MPL_ASSERT_RELATION(Pos, <=, static_cast<int>(Array::static_size));
  31
  32         typedef mpl::int_<Pos> index;
  33         typedef Array array_type;
  34
  35         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  36         array_iterator(Array& a)
  37             : array(a) {}
  38
  39         Array& array;
  40
  41         template <typename Iterator>
  42         struct value_of
  43         {
  44             typedef typename Iterator::array_type array_type;
  45             typedef typename array_type::value_type type;
  46         };
  47
  48         template <typename Iterator>
  49         struct deref
  50         {
  51             typedef typename Iterator::array_type array_type;
  52             typedef typename
  53                 mpl::if_<
  54                     is_const<array_type>
  55                   , typename array_type::const_reference
  56                   , typename array_type::reference
  57                 >::type
  58             type;
  59
  60             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  61             static type
  62             call(Iterator const & it)
  63             {
  64                 return it.array[Iterator::index::value];
  65             }
  66         };
  67
  68         template <typename Iterator, typename N>
  69         struct advance
  70         {
  71             typedef typename Iterator::index index;
  72             typedef typename Iterator::array_type array_type;
  73             typedef array_iterator<array_type, index::value + N::value> type;
  74
  75             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  76             static type
  77             call(Iterator const& i)
  78             {
  79                 return type(i.array);
  80             }
  81         };
  82
  83         template <typename Iterator>
  84         struct next : advance<Iterator, mpl::int_<1> > {};
  85
  86         template <typename Iterator>
  87         struct prior : advance<Iterator, mpl::int_<-1> > {};
  88
  89         template <typename I1, typename I2>
  90         struct distance : mpl::minus<typename I2::index, typename I1::index>
  91         {
  92             typedef typename
  93                 mpl::minus<
  94                     typename I2::index, typename I1::index
  95                 >::type
  96             type;
  97
  98             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  99             static type
 100             call(I1 const&, I2 const&)
 101             {
 102                 return type();
 103             }
 104         };
 105
 106     private:
 107
 108         array_iterator<Array, Pos>& operator=(array_iterator<Array, Pos> const&);
 109     };
 110 }}
 111
 112 #ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
 113 namespace std
 114 {
 115     template <typename Array, int Pos>
 116     struct iterator_traits< ::boost::fusion::array_iterator<Array, Pos> >
 117     { };
 118 }
 119 #endif
 120
 121 #endif