Question

So in my program I have some classes – Button, Window and WindowButton. Button consists only of text, Window – of a button and coordinates(x,y), and WindowButton consists of a Window.
In WindowButton, I have overloaded the << operator like this:

ostream& operator<<(ostream& out, WindowButton& ref)
{
    ref.print();
    return out;
}

Where the print function looks like:

void WindowButton::print()
{
    theWindow->print();
}

And the window print function, in window class:

void Window::print()
{
    char* buttonText = button->getText();
    char* theText = new char[strlen(buttonText)+1];
    strcpy(theText, buttonText);
    cout << endl << "Window with coordinates (" << this->coord.x << "," << this->coord.y << ") , and button text \"" << theText << "\"" << endl;
}

In main:

WindowButton *test = new WindowButton();
cout << endl << test;
test->print();

The last line provides the right output, but the second line provides just a memory adress. What am I doing wrong? Everything should be working fine, because the test->print(); works fine.

Answer 1

You are passing a pointer to operator<< which expects a &.

cout << endl << *test;

You might also make it:

ostream& operator<<(ostream& out, const WindowButton& ref){

Which assumes print doesn’t actually modify.

But, the bigger question is why are you using the cout ostream to trigger printing to theWindow — these appear to be (though aren’t) logically disconnected processes. You could pass the given stream into Window::print:

void Window::print(ostream& stream) {

and use that stream in place of cout. This avoids hard-coding cout into Window::print().