I have 2d array, that represents matrix and I need to print it via overloaded << operator.

The declaration of that overloaded operator is

```
std::ostream &operator <<(std::ostream &os, const Matrix &matrix) {

return os;
}

```

and it works well - when I write 

```
 ostringstream os;
 Matrix a;
 // fill in the matrix
 os << a;

```

this function is called...but although I've read some tutorials, I didn't find out, how to make it to print out the values... Can somebody pls show me on soma sample code, how to implement some very basic operation of printing out the values from matrix?

btw-the matrixes can have random sizes..