ceph/src/boost/libs/fusion/include/boost/fusion/adapted/std_array/std_array_iterator.hpp

   1 /*=============================================================================
   2     Copyright (c) 2013 Mateusz Loskot
   3     Copyright (c) 2001-2011 Joel de Guzman
   4     Copyright (c) 2005-2006 Dan Marsden
   5
   6     Distributed under the Boost Software License, Version 1.0. (See accompanying
   7     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   8 ==============================================================================*/
   9 #if !defined(BOOST_FUSION_STD_ARRAY_ARRAY_ITERATOR_01062013_1700)
  10 #define BOOST_FUSION_STD_ARRAY_ARRAY_ITERATOR_01062013_1700
  11
  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 #include <boost/fusion/adapted/std_array/detail/array_size.hpp>
  21
  22 namespace boost { namespace fusion
  23 {
  24     struct random_access_traversal_tag;
  25
  26     template <typename Array, int Pos>
  27     struct std_array_iterator
  28         : iterator_facade<std_array_iterator<Array, Pos>, random_access_traversal_tag>
  29     {
  30         BOOST_MPL_ASSERT_RELATION(Pos, >=, 0);
  31         BOOST_MPL_ASSERT_RELATION(Pos, <=, std::tuple_size<Array>::value);
  32
  33         typedef mpl::int_<Pos> index;
  34         typedef Array array_type;
  35
  36         std_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             static type
  61             call(Iterator const & it)
  62             {
  63                 return it.array[Iterator::index::value];
  64             }
  65         };
  66
  67         template <typename Iterator, typename N>
  68         struct advance
  69         {
  70             typedef typename Iterator::index index;
  71             typedef typename Iterator::array_type array_type;
  72             typedef std_array_iterator<array_type, index::value + N::value> type;
  73
  74             static type
  75             call(Iterator const& i)
  76             {
  77                 return type(i.array);
  78             }
  79         };
  80
  81         template <typename Iterator>
  82         struct next : advance<Iterator, mpl::int_<1> > {};
  83
  84         template <typename Iterator>
  85         struct prior : advance<Iterator, mpl::int_<-1> > {};
  86
  87         template <typename I1, typename I2>
  88         struct distance : mpl::minus<typename I2::index, typename I1::index>
  89         {
  90             typedef typename
  91                 mpl::minus<
  92                     typename I2::index, typename I1::index
  93                 >::type
  94             type;
  95
  96             static type
  97             call(I1 const&, I2 const&)
  98             {
  99                 return type();
 100             }
 101         };
 102
 103     private:
 104
 105         std_array_iterator<Array, Pos>& operator=(std_array_iterator<Array, Pos> const&);
 106     };
 107 }}
 108
 109 #endif