use overload;
use Carp;

sub flatten {
    my $ref  = shift;
    my $seen = shift || "";
    return map {
        (UNIVERSAL::isa($_,"ARRAY")) ? do {
            my $ref_str=overload::StrVal($_);
            Carp::croak "Cant flatten cyclic data structure !"
                if index($seen,$ref_str)>=0;
            flatten($_,$seen."$ref_str");
        } : $_ #change to #} : $_ ? $_ :()# to simulate grep
        } @$ref;
}

require Data::Dumper;
print Data::Dumper::Dumper([
     flatten([qw(array of elements),
              [qw(and arrays)],
              bless [qw(even blessed ones)],"FooArray"
             ])
]);
__END__
$VAR1 = [
          'array',
          'of',
          'elements',
          'and',
          'arrays',
          'even',
          'blessed',
          'ones'
        ];