class Base
  {
  public:
    Base() {};
    virtual ~Base() {}
  };
  
  class Derived : public Base
  {
  public:
    Derived() {}
    virtual ~Derived() {}
  };
  
  int main(int argc, char** argv)
  {
    Base* b;
    Derived* d = new Derived();
  
    b = d; // Don.t need a cast to go up the inheritance hierarchy
    d = static_cast<Derived*>(b); // Need a cast to go down the hierarchy
  
    Base base;
    Derived derived;
  
    Base& br = base;
    Derived& dr = static_cast<Derived&>(br);
  
    int i = 3;
    double result = static_cast<double>(i) / 10;
  
    return (0);
  }