c-electric-delete is an interactive compiled Lisp function in `cc-cmds.el'.

(c-electric-delete ARG)

Deletes preceding or following character or whitespace.
This function either deletes forward as `c-electric-delete-forward' or
backward as `c-electric-backspace', depending on the configuration: If
the function `delete-forward-p' is defined and returns non-nil, it
deletes forward. Otherwise it deletes backward.

Note: This is the way in XEmacs to choose the correct action for the
[delete] key, whichever key that means. Other flavors don't use this
function to control that.