ceph/src/boost/boost/spirit/home/karma/detail/indirect_iterator.hpp

   1 //  Copyright (c) 2001-2011 Hartmut Kaiser
   2 //
   3 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
   4 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #ifndef BOOST_SPIRIT_KARMA_DETAIL_INDIRECT_ITERATOR_HPP
   7 #define BOOST_SPIRIT_KARMA_DETAIL_INDIRECT_ITERATOR_HPP
   8
   9 #if defined(_MSC_VER)
  10 #pragma once
  11 #endif
  12
  13 #include <boost/spirit/home/support/unused.hpp>
  14 #include <boost/iterator/iterator_facade.hpp>
  15 #include <iterator> // for std::iterator_traits
  16
  17 ///////////////////////////////////////////////////////////////////////////////
  18 namespace boost { namespace spirit { namespace karma { namespace detail
  19 {
  20     ///////////////////////////////////////////////////////////////////////
  21     // This is a wrapper for any iterator allowing to pass a reference of it
  22     // to the components of the sequence
  23     template <typename Iterator>
  24     class indirect_iterator
  25       : public boost::iterator_facade<
  26             indirect_iterator<Iterator>
  27           , typename std::iterator_traits<Iterator>::value_type
  28           , boost::forward_traversal_tag
  29           , typename std::iterator_traits<Iterator>::reference>
  30     {
  31         typedef typename std::iterator_traits<Iterator>::value_type
  32             base_value_type;
  33         typedef typename std::iterator_traits<Iterator>::reference
  34             base_reference_type;
  35
  36         typedef boost::iterator_facade<
  37             indirect_iterator<Iterator>, base_value_type
  38           , boost::forward_traversal_tag, base_reference_type
  39         > base_type;
  40
  41     public:
  42         indirect_iterator(Iterator& iter)
  43           : iter_(&iter)
  44         {}
  45         indirect_iterator(indirect_iterator const& iter)
  46           : iter_(iter.iter_)
  47         {}
  48
  49     private:
  50         friend class boost::iterator_core_access;
  51
  52         void increment()
  53         {
  54             ++*iter_;
  55         }
  56
  57         bool equal(indirect_iterator const& other) const
  58         {
  59             return *iter_ == *other.iter_;
  60         }
  61
  62         base_reference_type dereference() const
  63         {
  64             return **iter_;
  65         }
  66
  67     private:
  68         Iterator* iter_;
  69     };
  70 }}}}
  71
  72 ///////////////////////////////////////////////////////////////////////////////
  73 namespace boost { namespace spirit { namespace traits
  74 {
  75     template <typename Iterator>
  76     struct make_indirect_iterator
  77     {
  78         typedef karma::detail::indirect_iterator<Iterator> type;
  79     };
  80
  81     template <typename Iterator>
  82     struct make_indirect_iterator<karma::detail::indirect_iterator<Iterator> >
  83     {
  84         typedef karma::detail::indirect_iterator<Iterator> type;
  85     };
  86
  87     template <>
  88     struct make_indirect_iterator<unused_type const*>
  89     {
  90         typedef unused_type const* type;
  91     };
  92
  93     template <typename Iterator>
  94     struct make_indirect_iterator<Iterator const&>
  95       : make_indirect_iterator<Iterator const>
  96     {};
  97 }}}
  98
  99 #endif