I don't believe you think that using caller to implement access control or interface selection is a reasonable idea. I don't believe that even though you just said it.

I know that kind of trick has been used to implement something like private or protected methods; I would rather not debate if it is reasonable or not.

What I have done is use caller information to decide how a routine behaves, so that if caller()->isa("Picky::Class"), the data passed is handled ... slightly differently.

What can I say? It seemed like a reasonable idea at the time.

... and it has worked without redesign for years now :-)

The Sidhekin
print "Just another Perl ${\(trickster and hacker)},"