//  A1_9.cpp

#include <iostream>
using namespace std;

class Y {
  public:
    Y& operator=(const Y &y) {
      if(this==&y) return *this;
      cout << "\n  assigning a Y object";
      return *this;
    }
};

class B {
  public:
    B& operator=(const B &b) {
      if(this==&b) return *this;
      cout << "\n  assigning a B object";
      return *this;
    }
};

class C : public B {
  Y y;
  public:
    C& operator=(const C &c) {
      if(this==&c) return *this;
      cout << "\n  assigning a C object";
      *(static_cast<B*>(this)) = c;

//// alternate syntax ///////////////////////////////////////////////////////
//    ((B&)*this) = c;     // always works, using old cast
//    B::operator=(c);     // works only if B defines operator=(...)
/////////////////////////////////////////////////////////////////////////////

      y = c.y;
      return *this;
    }
};

void main() {

  C c1, c2;
  c1 = c2;

  cout << "\n\n";
}