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Diffstat (limited to 'include/olm/list.hh')
-rw-r--r-- | include/olm/list.hh | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/include/olm/list.hh b/include/olm/list.hh new file mode 100644 index 0000000..e4bf951 --- /dev/null +++ b/include/olm/list.hh @@ -0,0 +1,119 @@ +/* Copyright 2015 OpenMarket Ltd + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#ifndef OLM_LIST_HH_ +#define OLM_LIST_HH_ + +#include <cstddef> + +namespace olm { + +template<typename T, std::size_t max_size> +class List { +public: + List() : _end(_data) {} + + typedef T * iterator; + typedef T const * const_iterator; + + T * begin() { return _data; } + T * end() { return _end; } + T const * begin() const { return _data; } + T const * end() const { return _end; } + + /** + * Is the list empty? + */ + bool empty() const { return _end == _data; } + + /** + * The number of items in the list. + */ + std::size_t size() const { return _end - _data; } + + T & operator[](std::size_t index) { return _data[index]; } + + T const & operator[](std::size_t index) const { return _data[index]; } + + /** + * Erase the item from the list at the given position. + */ + void erase(T * pos) { + --_end; + while (pos != _end) { + *pos = *(pos + 1); + ++pos; + } + } + + /** + * Make space for an item in the list at a given position. + * If inserting the item makes the list longer than max_size then + * the end of the list is discarded. + * Returns the where the item is inserted. + */ + T * insert(T * pos) { + if (_end != _data + max_size) { + ++_end; + } else if (pos == _end) { + --pos; + } + T * tmp = pos; + while (tmp != _end - 1) { + *(tmp + 1) = *tmp; + ++tmp; + } + return pos; + } + + /** + * Make space for an item in the list at the start of the list + */ + T * insert() { return insert(begin()); } + + /** + * Insert an item into the list at a given position. + * If inserting the item makes the list longer than max_size then + * the end of the list is discarded. + * Returns the where the item is inserted. + */ + T * insert(T * pos, T const & value) { + pos = insert(pos); + *pos = value; + return pos; + } + + List<T, max_size> & operator=(List<T, max_size> const & other) { + if (this == &other) { + return *this; + } + T * this_pos = _data; + T * const other_pos = other._data; + while (other_pos != other._end) { + *this_pos = *other; + ++this_pos; + ++other_pos; + } + _end = this_pos; + return *this; + } + +private: + T * _end; + T _data[max_size]; +}; + +} // namespace olm + +#endif /* OLM_LIST_HH_ */ |