Heh...
perl -E '
$o = bless \$o, 0;
*{"0::barf"} = sub {say "woof $_[1]"};
$foo = 0;
$foo->barf("warf");
say $o;
$o->barf("chrrr, wuff!");
0->barf("what?")'
woof warf
0=REF(0x1267880)
woof chrrr, wuff!
woof what?
This is part of perl's flexibility I dearly love, and that shouldn't go away. I could - if there was a need for it! - even make integers into packages and let them have their own methods. Although those integers are strings as package names, perls builtin conversions just dwim.
perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'