// B2.4.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream>
using namespace std;

// Define a base class B and two derived classes D1 and D2 so that 
// B provides a function that a client can use to create an instance
// of either derived class, as shown below.  
//
// B should not have to know the names of the derived classes:
//
// D1 d1;  D1 *pD1 = D1::create();
// D2 d2;  D2 *pD2 = D2::create();
//
// To build this application you need to enable RTTI using project
// properties.  Get to that by right clicking on the project name.

//// a complete answer ////////////////////////

template <class T> class B { 
  public:
    virtual ~B() {}
    static T* create() { return new T; }
    virtual void showSelf() { 
      cout << "\n  " << typeid(*this).name();
    }
};
class D1 : public B<D1> { };
class D2 : public B<D2> { };

///////////////////////////////////////////////

int _tmain(int argc, _TCHAR* argv[])
{
  std::cout << "\n  Exam B2 - Question #4 "
            << "\n =======================\n";


  D1 d1; D1 *pD1 = D1::create(); pD1->showSelf(); delete pD1;
  D2 d2; D2 *pD2 = D2::create(); pD2->showSelf(); delete pD2;
  cout << "\n\n";

  return 0;
}