It undefines the subroutine that was previously defined
as my_sub. It does so by getting the CODE ref part of the
"my_sub" typeglob, then undefining the subroutine that
that code ref references.
Since the goal of this is to replace that
subroutine, this prevents the warning you would otherwise
get (when you
have warnings enabled) that "subroutine SUB has been
redefined". | [reply] |