#!/usr/bin/perl -w

package Foo;
use strict;

sub AUTOLOAD
{
    no strict qw(refs vars);
    my $pkg = __PACKAGE__;

    $AUTOLOAD =~ s/${pkg}:://;

    return if $AUTOLOAD eq 'DESTROY';

    if(exists $_[0]->{$AUTOLOAD}) {
        no strict 'refs';
        *{$AUTOLOAD} = sub {

            $_[1]    ?    $_[0]->{$AUTOLOAD} = $_[1]
                     :    $_[0]->{$AUTOLOAD};
        }
    } 
    else {
        die "Can't locate object method \"$AUTOLOAD\" via package \"$p
+kg\"";
    }
    
    &{$AUTOLOAD}(@_);    
}

sub new
{
    bless {foo => "bar"}, ref($_[0]) || $_[0];
}


package main;
use strict;

my $foo = new Foo;
print $foo->foo, "\n";
print $foo->foo("bas"), "\n";
print $foo->foo, "\n";
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Update: Thanks to chipmunk for pointing out a regex problem.