src/util/forward-pointer-iterator.h

   1 /*
   2  * Inkscape::Util::ForwardPointerIterator - wraps a simple pointer
   3  *                                          with various strategies
   4  *                                          to determine sequence
   5  *
   6  * Authors:
   7  *   MenTaLguY <mental@rydia.net>
   8  *
   9  * Copyright (C) 2004 MenTaLguY
  10  *
  11  * Released under GNU GPL, read the file 'COPYING' for more information
  12  */
  13
  14 #ifndef SEEN_INKSCAPE_UTIL_FORWARD_POINTER_ITERATOR_H
  15 #define SEEN_INKSCAPE_UTIL_FORWARD_POINTER_ITERATOR_H
  16
  17 #include <iterator>
  18 #include "util/reference.h"
  19
  20 namespace Inkscape {
  21
  22 namespace Util {
  23
  24 template <typename BaseType, typename Strategy>
  25 class ForwardPointerIterator;
  26
  27 template <typename BaseType, typename Strategy>
  28 class ForwardPointerIterator<BaseType const, Strategy> {
  29 public:
  30     typedef std::forward_iterator_tag iterator_category;
  31     typedef typename Traits::Reference<BaseType const>::LValue value_type;
  32     typedef std::ptrdiff_t difference_type;
  33     typedef typename Traits::Reference<BaseType const>::LValue reference;
  34     typedef typename Traits::Reference<BaseType const>::RValue const_reference;
  35     typedef typename Traits::Reference<BaseType const>::Pointer pointer;
  36
  37     typedef ForwardPointerIterator<BaseType const, Strategy> Self;
  38
  39     ForwardPointerIterator() : _p(NULL) {}
  40     ForwardPointerIterator(pointer p) : _p(p) {}
  41
  42     operator pointer() const { return _p; }
  43     reference operator*() const { return *_p; }
  44     pointer operator->() const { return _p; }
  45
  46     bool operator==(Self const &other) const {
  47         return _p == other._p;
  48     }
  49     bool operator!=(Self const &other) const {
  50         return _p != other._p;
  51     }
  52
  53     Self &operator++() {
  54         _p = Strategy::next(_p);
  55         return *this;
  56     }
  57     Self operator++(int) {
  58         Self old(*this);
  59         operator++();
  60         return old;
  61     }
  62
  63     operator bool() const { return _p != NULL; }
  64
  65 private:
  66     pointer _p;
  67 };
  68
  69 template <typename BaseType, typename Strategy>
  70 class ForwardPointerIterator
  71 : public ForwardPointerIterator<BaseType const, Strategy>
  72 {
  73 public:
  74     typedef typename Traits::Reference<BaseType>::LValue value_type;
  75     typedef typename Traits::Reference<BaseType>::LValue reference;
  76     typedef typename Traits::Reference<BaseType>::RValue const_reference;
  77     typedef typename Traits::Reference<BaseType>::Pointer pointer;
  78
  79     typedef ForwardPointerIterator<BaseType const, Strategy> Ancestor;
  80     typedef ForwardPointerIterator<BaseType, Strategy> Self;
  81
  82     ForwardPointerIterator() : Ancestor() {}
  83     ForwardPointerIterator(pointer p) : Ancestor(p) {}
  84
  85     operator pointer() const {
  86         return const_cast<pointer>(Ancestor::operator->());
  87     }
  88     reference operator*() const {
  89         return const_cast<reference>(Ancestor::operator*());
  90     }
  91     pointer operator->() const {
  92         return const_cast<pointer>(Ancestor::operator->());
  93     }
  94
  95     Self &operator++() {
  96         Ancestor::operator++();
  97         return *this;
  98     }
  99     Self operator++(int) {
 100         Self old(*this);
 101         operator++();
 102         return old;
 103     }
 104 };
 105
 106 }
 107
 108 }
 109
 110 #endif
 111 /*
 112   Local Variables:
 113   mode:c++
 114   c-file-style:"stroustrup"
 115   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 116   indent-tabs-mode:nil
 117   fill-column:99
 118   End:
 119 */
 120 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :