overloaded << insertion operator isn't working correctly - c++

Question

So I can't figure out why my insertion operator isn't working for my list class. I've looked at it for a while and I think the syntax is correct for overloading. Not sure on this one. Any hints as to why it's not working?? Here's the code:
EDIT:Changed some code around to what it currently is right now.
Sorry, the problem specifically now is that I cannot get it to print anything out, it simple prints and empty line.
here's the driver:
#include <iostream>
#include "polynomial.h"
using namespace std;
int main(){
Polynomial* poly = new Polynomial();
poly->set_coefficient(3,2);
poly->set_coefficient(0,2);
poly->set_coefficient(3,1);
cout << "trying to print data" << endl;
cout << *poly << endl;
return 0;
}
Here's the header:
#ifndef _POLYNOMIAL_H_
#define _POLYNOMIAL_H_
#include <iostream>
class Polynomial {
public:
struct PolyNode {
int coefficient, degree;
struct PolyNode* next;
PolyNode(int c, int d, PolyNode* n): coefficient(c),degree(d),next(n){}
};
PolyNode* firstTerm;
Polynomial(): firstTerm(0) {}
struct PolyNode* get_first(){
return firstTerm;
}
//makes the term with degree d have a coefficient of c
void set_coefficient(int c, int d);
~Polynomial();
friend std::ostream& operator<<(std::ostream& o, const Polynomial& p);
};
#endif
Here's the implementation:
#include "polynomial.h"
#include <iostream>
#include <ostream>
using namespace std;
void Polynomial::set_coefficient(int c, int d){
PolyNode* start = firstTerm;
if(c != 0 && firstTerm == 0)
firstTerm = new PolyNode(c,d,NULL);
else{
cout << "Entered set_coefficient()" << endl;
while(start->degree != d && start->next != NULL){
cout << "Inside set_coefficient() while loop" << endl;
start = start->next;
}
if(c != 0 && start == 0)
start = new PolyNode(c,d,0);
else if(c!= 0 && start != 0)
start->coefficient = c;
else if(c == 0){
cout << "deleting a term" << endl;
delete start;
}
}
cout << "Leaving set_coefficient()" << endl;
}
ostream& operator<<(ostream& o,const Polynomial& p){
Polynomial::PolyNode* start = p.firstTerm;
for(unsigned int i = 0; start->next != 0; i++){
o << "Term " << i << "'s coefficient is: " << start->coefficient << " degree is: " << start->degree << endl << flush;
start = start->next;
}
return o;
}

Answer 1

poly is a pointer, to use your custom operator << you need to say
cout << *poly; // output the object pointed-to, not the pointer itself
You haven't overloaded what it means to insert a Polynomial*. Nor should you try.
Besides that, you probably should accept the object by const reference, there's no reason for a stream output operator to go changing the object.