This is my code:

class Base { /* something */ };
class Derived : public Base { /* something */ };
vector<Base*> v; // somebody else initializes it, somewhere
int counter = 0; 
for (vector<Base*>::iterator i=v.begin(); i!=v.end(); ++i) {
  if (typeof(*i) == "Derived") { // this line is NOT correct
    counter++;
  }
}
cout << "Found " << counter << " derived classes";

One line in the code is NOT correct. How should I write it properly? Many thanks in advance!