C++ dynamic_cast Dynamic cast used to test type of object

//RTTI must be enabled in compiler
#include <iostream>
#include <typeinfo>           //for dynamic_cast
using namespace std;
class Base//from   www .  j av  a  2 s .  co m
{
   virtual void vertFunc()    //needed for dynamic cast
   {  }
};
class Derv1 : public Base
{  };
class Derv2 : public Base
{  };

//checks if pUnknown points to a Derv1
bool isDerv1(Base* pUnknown)  //unknown subclass of Base
{
   Derv1* pDerv1;
   if( pDerv1 = dynamic_cast<Derv1*>(pUnknown) )
      return true;
   else
      return false;
}
int main()
{
      Derv1* d1 = new Derv1;
      Derv2* d2 = new Derv2;
      if( isDerv1(d1) )
         cout << "d1 is a member of the Derv1 class\n";
      else
         cout << "d1 is not a member of the Derv1 class\n";
      if( isDerv1(d2) )
            cout << "d2 is a member of the Derv1 class\n";
      else
            cout << "d2 is not a member of the Derv1 class\n";
      return 0;
}