pp_pos       - Adds lvalue magic
pp_substr    - Adds lvalue magic
pp_vec       - Adds lvalue magic
pp_aelem     - Extends array
pp_aelemfast - Extends array
pp_aslice    - Extends array
pp_helem     - Extends hash
pp_hslice    - Extends hash
pp_padsv     - No effect as far as I can tell
pp_rv2sv     - ???
pp_rv2av     - ???
pp_rv2gv     - ???