Doubt about operator overloading << as a friend function

[chirag403]

Hey guys!

I have a small doubt regarding the overloading of the << operator for a simple class as a friend function. Consider the example below:

class Something
{
private:
    int x,y;

public:
    Something(int x, int y) : x(x), y(y) {}

int getX() {return x;}
int getY() {return y;}

friend std::ostream& operator<< (std::ostream &out, const Something &s);
};

Now in my definition for the overloaded << function, I noticed that using the access functions to get the x and y values and display them works (s.getX()). However since this is a friend function doing s.x also works.

What I want to know is what is better to do in such a situation. Which is more efficient? I'd guess direct access of member variables since the other one would have an extra function call?

Thanks in advance.

[moorecm]

The compile may inline the accessor methods making them about the same. If this class is used extensively (as would be for graphics or something), I would probably use the friend function and direct access to its members. Otherwise (read as: in most cases), I would just use it's public interface and not require the friend declaration.

[ne555]

The idea of making it friend is that you don't need to provide the class with unnecessary accessors.
Considerer it part of the interface