Question

I have a polynomial implementation in a linked list and want to do std::ostream overloading operation but it gives my an error that no match for ‘operator<<’ in ‘std::cout << p5’

That’s my implementation but when I test it through cout << p5 I get the aforementioned error.

UPDATE:
header file:

struct term{
    double coef;
    unsigned deg;
    struct term * next;
};
class Polynomial {
public:
    constructors etc
    overloading functions
   friend ostream& operator << (ostream& out,const term& object);
}

then in other file poly.cpp i have:

 ostream & operator << (ostream& out, const Polynomial object){
        term* q = object.getptr();
        if (object.getptr() == NULL)
            out << "( )";
        else
            while(q != NULL)
            {
                out << q->coef << "x^" << q->deg << " ";
                q = q->next;
            }
        return out;
    }

in main.cpp
Polynomial p5, then added some terms and cout << p5 but I get errors.

Answer 1

I think it’s your declarations which are causing the problem:

friend ostream & operator << (ostream & out, const term & object);

and

ostream & operator << (ostream & out, const Polynomial & object);

These don’t match. One is using a term object and the latter is using a Polynomial object. I’m assuming you want this function to use a term object because the function uses data memebers specific to the struct term. So change the latter to accept a term object:

ostream & operator << (ostream & out, const term & object);