[Boost-users] any_cast on polymoprhic types?

Is there a way to use any_cast for polymorphic types? For instance, let's say I've got a Base class and a Derived class. I want to be able to any_cast a Derived * to a Base * successfully, like so: class Base { virtual ~Base() {} }; class Derived : public Base { virtual ~Derived() {} }; Derived d; boost::any a = &d; boost::any_cast(a); // Will NOT throw an exception Thanks! --Steve