TwoWayList.h

#ifndef _TWO_WAY_LIST_H
#define _TWO_WAY_LIST_H

template<class Type>
class TwoWayList {

public:

    // basic constructor function
    TwoWayList();

    // deconstructor function
    ~TwoWayList();

    // swap operator
    void operator&=(TwoWayList &List);

    // add to current pointer position
    void Insert(Type *Item);

    // remove from current position
    void Remove(Type *Item);

    // get a reference to the current item, plus the offset given
    Type *Current(int offset);

    // move the current pointer position backward through the list
    void Retreat();

    // move the current pointer position forward through the list
    void Advance();

    // operations to check the size of both sides
    int LeftLength();

    int RightLength();

    // operations to swap the left and right sides of two lists
    void SwapLefts(TwoWayList &List);

    void SwapRights(TwoWayList &List);

    // operations to move the the start of end of a list
    void MoveToStart();

    void MoveToFinish();

    TwoWayList(TwoWayList &List);

private:

    struct Node {
        // data
        Type *data;
        Node *next;
        Node *previous;

        // constructor
        Node() : data(0), next(0), previous(0) {}

        // deconstructor
        ~Node() {
            delete data;
        }
    };


    struct Header {
        // data
        Node *first;
        Node *last;
        Node *current;
        int leftSize;
        int rightSize;
    };

    // the list itself is pointed to by this pointer
    Header *list;

};

#endif