Revert "fix lint warning"

This reverts commit 4a9e281a7d42595354c775ee1a79fdb9c3ec6354.
Revert "register_smart_ptr changed to .shared_ptr (mod to class definition) -- shared_ptr (outside of class definition) is still allowed"

This reverts commit c38bb38e9d6393dfacb4afb0e9ba80ce42aee965.