C++ double linked list

#include <iostream>
using namespace std;

template <class T> class DblList;

template <class T>
struct DblNode
{
	friend class DblList<T>;
public:
	DblNode(T &dt) :data(dt) {}
	DblNode() {}
//private:
	T data;
	DblNode *lLink;
	DblNode *rLink;
};

template <class T>
class DblList
{
public:
	DblList() 
	{
		first = new DblNode<T>();
		first->lLink = first->rLink = first;
	};
	DblNode<T> * getFirst()
	{
		return first;
	}
	//在p1的右边插入p2
	void Insert(DblNode<T> * p1, DblNode<T> * p2);
	void Delete(DblNode<T> * p);

private:
	DblNode<T> *first;
};

template <class T>
void DblList<T>::Insert(DblNode<T> * p1, DblNode<T> * p2)
{
	p2->lLink = p1;
	p2->rLink = p1->rLink;

	p1->rLink->lLink = p2;
	p1->rLink = p2;
}

template <class T>
void DblList<T>::Delete(DblNode<T> * p)
{
	if (p == first)
		return;

	p->lLink->rLink = p->rLink;
	p->rLink->lLink = p->lLink;

	delete p;
}


int main()
{
	DblList<int> iDl;

	
	int a1 = 10, a2 = 20, a3 = 30, a4 = 40;
	DblNode<int> *node1 = new DblNode<int>(a1);
	DblNode<int> *node2 = new DblNode<int>(a2);
	DblNode<int> *node3 = new DblNode<int>(a3);
	DblNode<int> *node4 = new DblNode<int>(a4);

	iDl.Insert(iDl.getFirst(),node1);
	iDl.Insert(iDl.getFirst(), node2);
	iDl.Insert(iDl.getFirst(), node3);
	iDl.Insert(iDl.getFirst(), node4);
	

	cout<< iDl.getFirst() ->rLink->data<<endl;
	cout << iDl.getFirst()->rLink->rLink->data << endl;
	cout << iDl.getFirst()->rLink->rLink->rLink->data << endl;
	cout << iDl.getFirst()->rLink->rLink->rLink->rLink->data << endl;

	cout << endl << endl;

	iDl.Delete(node1);
	iDl.Delete(node4);

	cout << iDl.getFirst()->rLink->data << endl;
	cout << iDl.getFirst()->rLink->rLink->data << endl;
	//cout << iDl.getFirst()->rLink->rLink->rLink->data << endl;
	
	return 0;
}

operation result: