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 #if !defined(SPIRIT_KARMA_INDIRECT_ITERATOR_JAN_19_2011_0814PM)
   7 #define SPIRIT_KARMA_INDIRECT_ITERATOR_JAN_19_2011_0814PM
   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
  16 ///////////////////////////////////////////////////////////////////////////////
  17 namespace boost { namespace spirit { namespace karma { namespace detail
  18 {
  19     ///////////////////////////////////////////////////////////////////////
  20     // This is a wrapper for any iterator allowing to pass a reference of it
  21     // to the components of the sequence
  22     template <typename Iterator>
  23     class indirect_iterator
  24       : public boost::iterator_facade<
  25             indirect_iterator<Iterator>
  26           , typename boost::detail::iterator_traits<Iterator>::value_type
  27           , boost::forward_traversal_tag
  28           , typename boost::detail::iterator_traits<Iterator>::reference>
  29     {
  30         typedef typename boost::detail::iterator_traits<Iterator>::value_type
  31             base_value_type;
  32         typedef typename boost::detail::iterator_traits<Iterator>::reference
  33             base_reference_type;
  34
  35         typedef boost::iterator_facade<
  36             indirect_iterator<Iterator>, base_value_type
  37           , boost::forward_traversal_tag, base_reference_type
  38         > base_type;
  39
  40     public:
  41         indirect_iterator(Iterator& iter)
  42           : iter_(&iter)
  43         {}
  44         indirect_iterator(indirect_iterator const& iter)
  45           : iter_(iter.iter_)
  46         {}
  47
  48     private:
  49         friend class boost::iterator_core_access;
  50
  51         void increment()
  52         {
  53             ++*iter_;
  54         }
  55
  56         bool equal(indirect_iterator const& other) const
  57         {
  58             return *iter_ == *other.iter_;
  59         }
  60
  61         base_reference_type dereference() const
  62         {
  63             return **iter_;
  64         }
  65
  66     private:
  67         Iterator* iter_;
  68     };
  69 }}}}
  70
  71 ///////////////////////////////////////////////////////////////////////////////
  72 namespace boost { namespace spirit { namespace traits
  73 {
  74     template <typename Iterator>
  75     struct make_indirect_iterator
  76     {
  77         typedef karma::detail::indirect_iterator<Iterator> type;
  78     };
  79
  80     template <typename Iterator>
  81     struct make_indirect_iterator<karma::detail::indirect_iterator<Iterator> >
  82     {
  83         typedef karma::detail::indirect_iterator<Iterator> type;
  84     };
  85
  86     template <>
  87     struct make_indirect_iterator<unused_type const*>
  88     {
  89         typedef unused_type const* type;
  90     };
  91
  92     template <typename Iterator>
  93     struct make_indirect_iterator<Iterator const&>
  94       : make_indirect_iterator<Iterator const>
  95     {};
  96 }}}
  97
  98 #endif