Doubly Linked Lists Overview

This document is an overview of doubly linked lists.


Manipulates a doubly-linked list: an ordered, non-indexed list of elements, that can be traversed in both directions.

The API contains all the necessary functionality for doubly-linked lists. It is possible to derive from its classes to add additional features.


The API has three key concepts: list header (TDblQue), link class (TDblQueLink), and iterator class (TDblQueIter).

General properties

Note the following properties of doubly-linked lists:

  • the list is circular: the last element points forward to the head element and the head element points back to the last element

  • elements can be accessed through iterating through the list, and added to the start and end of a list, but not to the middle

  • elements in a linked list need not be objects of the same type but ought to be derived from the same base class

List header

The list header supplies the behaviour for managing a doubly linked list of objects.

The list header interface is provided by TDblQue <class T>. The T template parameter specifies the type of objects in the list.

Link class

To be a member of a doubly linked list, an object must contain an instance of the link class as a data member.

The link class interface is provided by TDblQueLink.

Iterator class

The iterator class supplies the behaviour for moving through the elements of a list.

The iterator class interface is provided by TDblQueIter.