can you access private member variables across class instances?

Question

I didn\'t think it was possible, but if you have two instances of the same class, are you allowed to access one\'s private members from the other?

Is this why you ca

Answer 1

Access restrictions are a property of the class, not of an instance.

That's why you can write your usual copy constructor:

class Foo
{
     int a; // private!
public:
    Foo (Foo const & rhs) : a(rhs.a) { } // rhs.a is accessible
};

This idea is also what fuels the "factory" idiom:

class Bar
{
    Bar() { } // private?!
public:
    static Bar * create() { return new Bar(); } // Bar::Bar() is accessible
};