#!/usr/bin/perl
use warnings;
use strict;

{   package My;
    use overload
        '""' => sub { "@{ $_[0] }" };

    sub new {
        my $class = shift;
        bless [ @_ ], $class
    }
}

my $ar = 'My'->new(2, 3, 4, 5, 7);
print ref $ar ? "Reference\n" : "Not a reference\n";
print $ar, "\n";
[download]

Update: ref $ar returns "My" in this case, not "ARRAY". So it can't be the case here, unless the class is named ARRAY.