// Illustration of dynamic_cast in a classical polymorphic situation.

#include <iostream>
#include <string>

using namespace std;

class A {
  public: 
  virtual void f(){
    cout << "Here is f in A" << endl;
  }
};

class B: public A {
  public: 
  void f() override{
    cout << "Here is f in B" << endl;
  }
};

int main(){

  A* a = new B{};                   // a can point to a B-object
  a->f();                           // Here is f in B

  B* b1 = a;                        // error: invalid conversion from A* to B*
  b1->f();  

  B* b2 = dynamic_cast<B*>(a);      // Now OK with dynamic cast
  b2->f();                          // Here is f in B.

  // Attempting to enforce calling f from A from b2:
  dynamic_cast<A*>(b2)->f();        // Here is f in B.  Not successful.
  static_cast<A*>(b2)->f();         // Here is f in B.  Not successful.
  b2->A::f();                       // Here is f in A.  OK - thats the way to do it.  
}