Just to expand on this point for the OP's benefit, consider:

use strict;

use Dumpvalue;
my $dumper = Dumpvalue->new();

my @a = (3, 1, 4, 1);
my @b = (5, 9);
my @c = (2, 6, 5);

sub ex1 {
  map 10*$_, @_;
}

$dumper->dumpValue([ex1(@a)]);
print "\n";

# array refs
sub ex2 {
  map scalar @$_, @_;
}
$dumper->dumpValue([ex2(\@a, \@b, \@c)]);
print "\n";

# implicit array refs through prototypes
sub ex3 (\@\@\@) {
  map scalar @$_, @_;
}
$dumper->dumpValue([ex3(@a, @b, @c)]);
print "\n";

__END__
0  30
1  10
2  40
3  10

0  4
1  2
2  3

0  4
1  2
2  3
[download]

Follow-up question: is there any way to define a sub that takes as input one or more arrays?