#!/usr/local/bin/perl -w
use strict;
                                                                                
package ArrayOrString;
use overload
    '""'  => \&to_string;
                                                                                
my $STRING_VAL = '';
                                                                                
sub new {
    my ($class, $arrayref) = @_;
    die "not an array ref" unless 'ARRAY' eq ref $arrayref;
    bless $arrayref, $class;
}
                                                                                
sub string {
    shift;
    $STRING_VAL = shift if @_;
    return $STRING_VAL;
}
                                                                                
sub to_string {
    return $STRING_VAL;
}
                                                                                
package main;
                                                                                
my @bar = qw(one two three);
my $foo = ArrayOrString->new(\@bar);
$foo->string('bar');
print "*** $foo ***\n";
                                                                                
foreach my $baz (@$foo) {
    print "Val: $baz \n";
}