ladybird/AK/SinglyLinkedListWithCount.h
Brian Gianforcaro efb0805d8e AK: Add SinglyLinkedListWithCount<T>, a singulary linked list with count
There are use cases where a linked list is useful but it's also worth
the overhead to maintain a count so you can quickly answer queries of
the size of the list.
2020-08-05 09:34:22 +02:00

168 lines
3.9 KiB
C++

/*
* Copyright (c) 2020, Brian Gianforcaro <b.gianfo@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/SinglyLinkedList.h>
namespace AK {
template<typename T>
class SinglyLinkedListWithCount : private SinglyLinkedList<T> {
public:
SinglyLinkedListWithCount() {}
~SinglyLinkedListWithCount() {}
using List = SinglyLinkedList<T>;
using List::is_empty;
using List::size_slow;
inline size_t size() const
{
return m_count;
}
void clear()
{
List::clear();
m_count = 0;
}
T& first()
{
return List::first();
}
const T& first() const
{
return List::first();
}
T& last()
{
return List::last();
}
const T& last() const
{
return List::last();
}
T take_first()
{
m_count--;
return List::take_first();
}
void append(const T& value)
{
m_count++;
return SinglyLinkedList<T>::append(value);
}
void append(T&& value)
{
m_count++;
return List::append(move(value));
}
bool contains_slow(const T& value) const
{
return List::contains_slow(value);
}
using Iterator = List::Iterator;
friend Iterator;
Iterator begin() { return List::begin(); }
Iterator end() { return List::end(); }
using ConstIterator = List::ConstIterator;
friend ConstIterator;
ConstIterator begin() const { return List::begin(); }
ConstIterator end() const { return List::end(); }
template<typename Finder>
ConstIterator find(Finder finder) const
{
return List::find(finder);
}
template<typename Finder>
Iterator find(Finder finder)
{
return List::find(finder);
}
ConstIterator find(const T& value) const
{
return List::find(value);
}
Iterator find(const T& value)
{
return List::find(value);
}
void remove(Iterator iterator)
{
m_count--;
return List::remove(iterator);
}
void insert_before(Iterator iterator, const T& value)
{
m_count++;
List::insert_before(iterator, value);
}
void insert_before(Iterator iterator, T&& value)
{
m_count++;
List::insert_before(iterator, move(value));
}
void insert_after(Iterator iterator, const T& value)
{
m_count++;
List::insert_after(iterator, value);
}
void insert_after(Iterator iterator, T&& value)
{
m_count++;
List::insert_after(iterator, move(value));
}
private:
size_t m_count { 0 };
};
}
using AK::SinglyLinkedListWithCount;