// Example code, illustrating the hazards of routine type-casting in C++.

#include <iostream.h>

class Trouble {  };
class Party   { 
  public:
  int const numLegs;
  Party() : numLegs(4) { }    // C++ syntax for init'ing const numLegs as 4.
  };


int main() {
  Party *invitation = (Party*) (new Trouble());

  // Every Party->numLegs is 4, and
  // C++'s type system states that invitation is a Party*,
  // so surely:
  //
  cout << "My dog has " << invitation->numLegs << " legs and a tail!" << endl;

  return 0;
  }


// ===============================================================
// Output:
//
//     My dog has 246744 legs and a tail!
//
// Your mileage may vary, from one compiler/system to another.
// The root of the problem is the blatantly illegal type cast,
// which C++'s type system blithely allows, w/o so much as a peep:
// 
//     class Trouble { /* ...class details... */ };
//     class Party   { /* ...class details... */ };
//     
//     Party *invitation = (Party*) (new Trouble()); 
//     // C++ thinks invitation points to a Party, but really it is a Trouble.
//
// (Imagine trying to debug this, and discovering that changing
// the <em>order</em> in which classes are declared -- which should change
// nothing, according to every C++ manual -- <em>can</em> change the output!)