ceph/src/boost/tools/quickbook/src/iterator.hpp

   1 /*=============================================================================
   2     Copyright (c) 2010 Daniel James
   3
   4     Use, modification and distribution is subject to the Boost Software
   5     License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   6     http://www.boost.org/LICENSE_1_0.txt)
   7 =============================================================================*/
   8
   9 #if !defined(BOOST_SPIRIT_QUICKBOOK_ITERATOR_HPP)
  10 #define BOOST_SPIRIT_QUICKBOOK_ITERATOR_HPP
  11
  12 #include <boost/operators.hpp>
  13 #include <boost/iterator/iterator_traits.hpp>
  14 #include <boost/range/iterator_range.hpp>
  15 #include <iterator>
  16 #include "string_view.hpp"
  17
  18 namespace quickbook
  19 {
  20     template <typename Iterator>
  21     struct lookback_iterator
  22         : boost::forward_iterator_helper<
  23             lookback_iterator<Iterator>,
  24             typename boost::iterator_value<Iterator>::type,
  25             typename boost::iterator_difference<Iterator>::type,
  26             typename boost::iterator_pointer<Iterator>::type,
  27             typename boost::iterator_reference<Iterator>::type
  28         >
  29     {
  30         lookback_iterator() {}
  31         explicit lookback_iterator(Iterator i)
  32             : original_(i), base_(i) {}
  33
  34         friend bool operator==(
  35             lookback_iterator const& x,
  36             lookback_iterator const& y)
  37         {
  38             return x.base_ == y.base_;
  39         }
  40
  41         lookback_iterator& operator++()
  42         {
  43             ++base_;
  44             return *this;
  45         }
  46
  47         typename boost::iterator_reference<Iterator>::type operator*() const
  48         {
  49             return *base_;
  50         }
  51
  52         Iterator base() const {
  53             return base_;
  54         }
  55
  56         typedef boost::iterator_range<std::reverse_iterator<Iterator> >
  57             lookback_range;
  58
  59         lookback_range lookback() const
  60         {
  61             return lookback_range(base_, original_);
  62         }
  63
  64     private:
  65         Iterator original_;
  66         Iterator base_;
  67     };
  68
  69     typedef lookback_iterator<string_iterator> parse_iterator;
  70 }
  71
  72 #endif