use strict;
use warnings;
use Scalar::Util qw( refaddr );

package Foo;
use overload
    '0+'    => sub { 0 },
    q{""}   => sub { "Some Object" },
    fallback => 1;

package main;
use overload;

sub refaddr_pp {
    return if not ref $_[0];
    overload::StrVal($_[0]) =~ /0x(\w+)/;
    return hex $1;
}

my $obj = bless {}, 'Foo';
my $ref = {};

print 'stringify  $obj: ', "$obj",           "\n";
print 'refaddr    $obj: ', refaddr($obj),    "\n";
print 'refaddr_pp $obj: ', refaddr_pp($obj), "\n\n";
print 'stringify  $ref: ', "$ref",           "\n";
print 'refaddr    $ref: ', refaddr($ref),    "\n";
print 'refaddr_pp $ref: ', refaddr_pp($ref),    "\n\n";