| 1 | /* A "next" iterator for GDB, the GNU debugger. |
| 2 | Copyright (C) 2019-2020 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 | /* An iterator that uses the 'next' field of a type to iterate. This |
| 23 | can be used with various GDB types that are stored as linked |
| 24 | lists. */ |
| 25 | |
| 26 | template<typename T> |
| 27 | struct next_iterator |
| 28 | { |
| 29 | typedef next_iterator self_type; |
| 30 | typedef T *value_type; |
| 31 | typedef T *&reference; |
| 32 | typedef T **pointer; |
| 33 | typedef std::forward_iterator_tag iterator_category; |
| 34 | typedef int difference_type; |
| 35 | |
| 36 | explicit next_iterator (T *item) |
| 37 | : m_item (item) |
| 38 | { |
| 39 | } |
| 40 | |
| 41 | /* Create a one-past-the-end iterator. */ |
| 42 | next_iterator () |
| 43 | : m_item (nullptr) |
| 44 | { |
| 45 | } |
| 46 | |
| 47 | value_type operator* () const |
| 48 | { |
| 49 | return m_item; |
| 50 | } |
| 51 | |
| 52 | bool operator== (const self_type &other) const |
| 53 | { |
| 54 | return m_item == other.m_item; |
| 55 | } |
| 56 | |
| 57 | bool operator!= (const self_type &other) const |
| 58 | { |
| 59 | return m_item != other.m_item; |
| 60 | } |
| 61 | |
| 62 | self_type &operator++ () |
| 63 | { |
| 64 | m_item = m_item->next; |
| 65 | return *this; |
| 66 | } |
| 67 | |
| 68 | private: |
| 69 | |
| 70 | T *m_item; |
| 71 | }; |
| 72 | |
| 73 | /* A range adapter that allows iterating over a linked list. */ |
| 74 | |
| 75 | template<typename T, typename Iterator = next_iterator<T>> |
| 76 | class next_adapter |
| 77 | { |
| 78 | public: |
| 79 | |
| 80 | explicit next_adapter (T *item) |
| 81 | : m_item (item) |
| 82 | { |
| 83 | } |
| 84 | |
| 85 | using iterator = Iterator; |
| 86 | |
| 87 | iterator begin () const |
| 88 | { |
| 89 | return iterator (m_item); |
| 90 | } |
| 91 | |
| 92 | iterator end () const |
| 93 | { |
| 94 | return iterator (); |
| 95 | } |
| 96 | |
| 97 | private: |
| 98 | |
| 99 | T *m_item; |
| 100 | }; |
| 101 | |
| 102 | #endif /* COMMON_NEXT_ITERATOR_H */ |