Common code shared with other btl.autoptr modules .
Implementation of non-owning pointer GlobalPtr.
Implementation of intrusive reference counted pointer IntrusivePtr (similar to c++ std::enable_shared_from_this).
Implementation of non aliasable reference counted pointer RcPtr (similar to c++ std::shared_ptr without aliasing).
Implementation of reference counted pointer SharedPtr (similar to c++ std::shared_ptr).
Implementation of unique pointer UniquePtr (alias to btl.autoptr.rc_ptr.RcPtr with immutable control block).