no match for operator << ??

I posted the wrong code before sorry :) i was missing a #include <fstream>
i am a bit sleepy now but i gotta hand in the program tomorrow and the only thing left was splitting the files !

i get this error the first time i try to use the overloaded <<:
main.cpp: In function ‘int main(int, char**)’:
main.cpp:550: error: no match for ‘operator<<’ in ‘std::cout << fifolist

<< is overloaded to print the list ..

fifo.h code is :

Code:

---


class fifo{

//Other prototypes in the middle

    ostream& operator<<(ostream&);
};

---

and fifo.cpp :

Code:

---

ostream& operator<<(ostream &ons, fifo &object)
{
    vector <double>:: iterator theiterator;

    if (object.list_size()==0){
        cout<<"I fifo list einai keni!";
    }
    else
        cout<<endl<<"Fifo List  :";
    for(theiterator=object.list_begin();theiterator!=object.list_end();theiterator++)
        cout<<"  "<<*theiterator;
    cout<<endl;
}

---

Before i splitted the files i wasn't getting any errors.. Btw is there a tutorial online for splitting files with overloading >> or << ?

Did you include the appropriate stream header file in the file that this code came from?

for some reason, ye' code does not recognize the <iostream> library, which contains the functional implementation for the overloaded << insertion operator.

post edited and the includes are fine ! :)

Did you include a prototype for your << operator in a header file:

Code:

---

//probably in fifo.h
ostream& operator<<(ostream &ons, fifo &object);

---

i must get some rest... the one in the class isn't really the prototype..
I just realized that .. so i must include the real prototype outside the class.

thanks m8, it's just that my head is not working properly now and i didn't get it ..

There's a difference between these two:

Code:

---

class Foo
{
public:
ostream& operator<<(ostream&);
friend ostream& operator<<(ostream &ons, fifo &object);
};

---

The first you would use like this (and it doesn't really make sense):

Code:

---

foo myFoo;
myFoo<<std::cout;

---

The second is what you want, or actually in this case it doesn't look like it needs to even be a member function, so just put the prototype outside your class.

Edit: I meant to say, it doesn't need to be a friend function.