3rdparty/boost/boost/iterator/reverse_iterator.hpp

   1 // (C) Copyright David Abrahams 2002.
   2 // (C) Copyright Jeremy Siek    2002.
   3 // (C) Copyright Thomas Witt    2002.
   4 // Distributed under the Boost Software License, Version 1.0. (See
   5 // accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt)
   7 #ifndef BOOST_REVERSE_ITERATOR_23022003THW_HPP
   8 #define BOOST_REVERSE_ITERATOR_23022003THW_HPP
   9
  10 #include <boost/iterator/iterator_adaptor.hpp>
  11
  12 namespace boost {
  13 namespace iterators {
  14
  15   //
  16   //
  17   //
  18   template <class Iterator>
  19   class reverse_iterator
  20       : public iterator_adaptor< reverse_iterator<Iterator>, Iterator >
  21   {
  22       typedef iterator_adaptor< reverse_iterator<Iterator>, Iterator > super_t;
  23
  24       friend class iterator_core_access;
  25
  26    public:
  27       reverse_iterator() {}
  28
  29       explicit reverse_iterator(Iterator x)
  30           : super_t(x) {}
  31
  32       template<class OtherIterator>
  33       reverse_iterator(
  34           reverse_iterator<OtherIterator> const& r
  35           , typename enable_if_convertible<OtherIterator, Iterator>::type* = 0
  36           )
  37           : super_t(r.base())
  38       {}
  39
  40    private:
  41       typename super_t::reference dereference() const
  42       {
  43           Iterator it = this->base_reference();
  44           --it;
  45           return *it;
  46       }
  47
  48       void increment() { --this->base_reference(); }
  49       void decrement() { ++this->base_reference(); }
  50
  51       void advance(typename super_t::difference_type n)
  52       {
  53           this->base_reference() -= n;
  54       }
  55
  56       template <class OtherIterator>
  57       typename super_t::difference_type
  58       distance_to(reverse_iterator<OtherIterator> const& y) const
  59       {
  60           return this->base_reference() - y.base();
  61       }
  62   };
  63
  64   template <class BidirectionalIterator>
  65   inline reverse_iterator<BidirectionalIterator> make_reverse_iterator(BidirectionalIterator x)
  66   {
  67       return reverse_iterator<BidirectionalIterator>(x);
  68   }
  69
  70 } // namespace iterators
  71
  72 using iterators::reverse_iterator;
  73 using iterators::make_reverse_iterator;
  74
  75 } // namespace boost
  76
  77 #endif // BOOST_REVERSE_ITERATOR_23022003THW_HPP