LinkedListNode

template <typename ItemType>
class LinkedListNode
{
private:
    LinkedListNode<ItemType>* next;
    LinkedListNode<ItemType>* prev;
    LinkedListNode(const ItemType& value, LinkedListNode<ItemType>* nextNode, LinkedListNode<ItemType>* prevNode)
        : data(value), next(nextNode), prev(prevNode)
    {
        if (nextNode) nextNode->prev = this;
        if (prevNode) prevNode->next = this;
    }
public:
    ItemType data;
    LinkedListNode(const ItemType& value) :data(value) {
        next = prev = nullptr;
    }
    LinkedListNode<ItemType>* addAfter(const ItemType& value) {
        return new LinkedListNode<ItemType>(value, this->next, this);
    }
    LinkedListNode<ItemType>* addBefore(const ItemType& value) {
        return new LinkedListNode<ItemType>(value, this, this->prev);
    }
    LinkedListNode<ItemType>* operator[] (const int index) {
        int i = index;
        LinkedListNode<ItemType>* pointer = this;
        if (i >= 0)
        while (i-- && pointer->next)
            pointer = pointer->next;
        else
        while (i++ && pointer->prev)
            pointer = pointer->prev;
        return pointer;
    }
    void remove() {
        if (next)
            next->prev = prev;
        if (prev)
            prev->next = next;

        next = prev = nullptr;
        delete this;
    }

    ~LinkedListNode() {
        if (next)
            delete next;
        if (prev)
            delete prev;
    }
};