Can a pushdef pop itself dependably?

[Jack Woehr]

   $ cat popself.m4 
   define(`foo', `bar')dnl
   pushdef(`foo', `arf popdef(`foo') foo and then goodbye.
   m4exit')dnl
   $ gm4 popself.m4 -
   foo
   arf  bar and then goodbye.
   $


Can I depend on this sort of behavior ... that a pushdef can pop itself 
in the middle
and the revealed definition execute and the popped def finishes off 
before vanishing?

--
Jack J. Woehr            # "Self-delusion is
http://www.well.com/~jax #  half the battle!"
http://www.softwoehr.com #  - Zippy the Pinhead