A Static_cast<> Question

Suppose

Code:

---

class Derived: public Base{
...
};

---

what is the difference between:

Code:

---

Derived * d = new Derived;
Base* b = static_cast<Base*>(d);

---

AND

Code:

---

Derived  d ;
Base b = static_cast<Base>(d);

---

Polymorphic relationships don't hold for actual objects.

That is:

A Derived* is a Base*
A Derived& is a Base&

But a Derived is NOT a Base. Such a conversion results in slicing, and you lose pieces of your objects.

The second one makes a copy of the object and casts it (which is where the slicing happens). The first one makes a copy of the pointer and casts it, so the object is still there.