// A7.cpp - private void constructor used by a friend
//          private copy constructor used by another friend
//
// To create objects, even by a friend, we need another constructor.
// Otherwise, where would we get an object to copy. - I've provided
// a void constructor in the private area.

#include <iostream>
using namespace std;

class X {
  public:
    friend X* XCreator() { return new X; }
    friend void XCopier(const X &x) { 
      X newX = x;  
      newX.say(); 
    }
    void say() const { cout << "\n  an X object here!"; }
  private:
    X() { }
    X(const X &x) { }
};

/////////////////////////////////////////////////////////////////
//  This function won't compile since it is not a friend
//
//  X* AnotherXCreator() { return new X; }

void main() {

/////////////////////////////////////////////////////////////////
//X x;  this won't compile, since default constructor is private.

  X *pX = XCreator();
  pX->say();

/////////////////////////////////////////////////////////////////
// Note that even though XCopier is a friend it can not accept
// or return X objects by value.  It can only make copies internally.

  XCopier(*pX);

  cout << "\n\n";
}