Thread: Lists, the first step. Create the 'head node'?

Hi,

I am trying to store pointers to some inherited classes within a linked list, but am stuck with the first part.

I understand that each node contains two pointers to the next and previous, but how should I create the first 'head node' that points to the first object that will be added?

Here is my code:

header file :

Code:

class Vehicle
{
friend class listclass;

public:	
	Vehicle(int publicmpg = 0); 

protected:
	Vehicle *llink, *rlink;

	int protectedmpg;  
};

Vehicle::Vehicle(int publicmpg) 
{
	protectedmpg = publicmpg; 	
}

//-------------------------
//
//-------------------------

class Listclass
{
public:
	
	//addvehicle()
	Listclass(int publicfirst = 0);

protected:

	int protectedfirst; 
};

Listclass::Listclass(int publicfirst)
{
	protectedfirst = publicfirst;
}

//-------------------------
//
//-------------------------

class SportsCar : public Vehicle
{
public:
	SportsCar(int publicsixspeed = 0, int publicmpg = 0);

protected:
	int protectedsixspeed;
};

SportsCar::SportsCar(int publicsixspeed, int publicmpg) : Vehicle(publicmpg) 
{
	protectedsixspeed = publicsixspeed;
}

main.cpp :

Code:

#include <iostream>
#include <list>
#include "Vehicle.h"

using namespace std;

int main()
{
	list<Vehicle*> listname;

	Listclass headnode;

	//     Should I create the 'head node' here before
	//     going on to creating actual objects?

	int publicmpg = 11;
	int publicsixspeed = 22;

	SportsCar node(publicmpg, publicsixspeed);

	SportsCar *ptrToSportsCar;

	ptrToSportsCar = &node;

	listname.push_back( ptrToSportsCar );

	cout << "past push" << endl;

	system ("PAUSE");
	return 0;

How/should I create the 'head node' first, and then add the first items to the list?

I've read up and understand the 'head node' will only contain a pointer to the first node in the list, but how do I create it?.

I thought it might be easiest to create a single link list first, then try modify it into a doubly linked list.


Once I have the list established I think I'll be fine adding new items to the list, but I'm stuck 'getting it all setup' if you like.

Appreciate anyone's advice.

Thanks!