Suppose we have a class as

class Egg
{
static Egg e;
int i;
Egg(int ii):i(ii) {}
Egg(const Egg &);    //Prevents copy-constructor to be called
public:
static Egg* instance() {return &e}
};

Egg Egg::e(47);

This code guarantees that we cannot create any object, but could use only the static object. But how could we declare static object of the same class in the class.

And also one thing more since e is a static object, and static objects can call only static member functions, so how could the constructor been called here for static object e, also its constructors are private.