I'm missing something here, or I wasn't clear. Here's some code:

# untested

package Foo;

sub bleep {...}
sub baz { ... }

package NewFoo;
use base qw(Foo);

sub baz { ... }

package main;

my $a = Foo->new;
my $b= NewFoo->new;

$a->bleep;
$b->bleep;

$a->baz;
$b->baz;
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In this example, I am cool with a user calling bleep on either 'a' or 'b'. I'm also cool with a user calling baz on either 'a' or 'b'. What I'd like to detect from Foo is that a subclass (NewFoo) overrode a certain method. That is, $b->baz calls NewFoo::Baz, as that overrode Foo::Baz.

I'm looking for a way for Foo to detect and carp that a subclass took away its rights to own the code for method baz.

Probably this isn't "nice" OO -- "thou shalt never subclass me, dammnit" isnt friendly -- but I'm wondering how to do it anyway.

I really like the suggestion about just saying "never subclass baz" in the docs (++ to that post), but need something stronger.

The comments above about checking the ref on self don't seem relevant to me, as here the problem is that Foo::baz never gets involved when someone calls baz on $b... it is too late, the baz is then a NewFoo baz at that point.....?

water