Warning! Stunt code! 
package Before;
use Acme::Damn;

use overload
    '&{}' => sub {
        my $f = shift();
        my $ref = damn($f);
        return sub {
            print "Stuff before\n";
            my @rv = $ref->(@_);
            bless($ref, __PACKAGE__);
            return @rv;
        };
    };
1;

[download]
$ perl -MBefore -e 'my $foo = bless(sub { print shift()."\n" } => 'Bef
+ore'); $foo->("foo"); $foo->("bar")'
Stuff before
foo
Stuff before
bar

[download]
Acme::Damn is one of the very few Acme modules that I would consider using in real life. I use it here to temporarily unbless the object, then de-ref and call, and then re-bless it. It's not quite the same as your code though - because I call the subroutine instead of using goto, there's an extra stack frame and so if you use caller() inside it it will behave differently.

In reply to Re: Overloading without infinite descent by DrHyde
in thread Overloading without infinite descent (fixed by time: see Perl 5.10.1) by JadeNB

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