#include <iostream>
    #include <exception>
    using namespace std;
    class BaseClass 
    { 
        virtual void dummy() {} 
    };
    class DerivedClass: public BaseClass 
    { 
        int num; 
    };
    int main () 
    {
        try 
        {
            BaseClass * ptr1 = new DerivedClass;
            BaseClass * ptr2 = new BaseClass;
            DerivedClass * ptr3;
            ptr3 = dynamic_cast(ptr1);
            if (ptr3 == 0) 
                cout << "Null pointer on first type-cast" << endl;
            ptr3 = dynamic_cast(ptr2);
            if (ptr3 == 0) 
                cout << "Null pointer on second type-cast" << endl;
        } 
        catch (exception& excep) 
        {
            cout << "Exception: " << excep.what();
        }
        return 0;
    }