2009/11/5 Mario Klebsch <mkl@innodyne.de>
   boost::scoped_ptr<base_t> Ptr;
   Ptr.reset(new derived_t());

Prior to using a scoped_ptr, I could write:

   ((derived_t*)Ptr)->Method();

  ((derived_t*)Ptr->get())->Method();

or a safer version:
  static_cast<derived_t*>(Ptr->get())->Method();

Roman Perepelitsa.