1/* A "next" iterator for GDB, the GNU debugger.
2   Copyright (C) 2019-2023 Free Software Foundation, Inc.
3
4   This file is part of GDB.
5
6   This program is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 3 of the License, or
9   (at your option) any later version.
10
11   This program is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
18
19#ifndef COMMON_NEXT_ITERATOR_H
20#define COMMON_NEXT_ITERATOR_H
21
22#include "gdbsupport/iterator-range.h"
23
24/* An iterator that uses the 'next' field of a type to iterate.  This
25   can be used with various GDB types that are stored as linked
26   lists.  */
27
28template<typename T>
29struct next_iterator
30{
31  typedef next_iterator self_type;
32  typedef T *value_type;
33  typedef T *&reference;
34  typedef T **pointer;
35  typedef std::forward_iterator_tag iterator_category;
36  typedef int difference_type;
37
38  explicit next_iterator (T *item)
39    : m_item (item)
40  {
41  }
42
43  /* Create a one-past-the-end iterator.  */
44  next_iterator ()
45    : m_item (nullptr)
46  {
47  }
48
49  value_type operator* () const
50  {
51    return m_item;
52  }
53
54  bool operator== (const self_type &other) const
55  {
56    return m_item == other.m_item;
57  }
58
59  bool operator!= (const self_type &other) const
60  {
61    return m_item != other.m_item;
62  }
63
64  self_type &operator++ ()
65  {
66    m_item = m_item->next;
67    return *this;
68  }
69
70private:
71
72  T *m_item;
73};
74
75/* A convenience wrapper to make a range type around a next_iterator.  */
76
77template <typename T>
78using next_range = iterator_range<next_iterator<T>>;
79
80#endif /* COMMON_NEXT_ITERATOR_H */
81