use strict;
use warnings;
use feature 'say';
use Scalar::Util qw(refaddr);

my @data = (1, 2, 3);
my $a = \@data;
my $b = \@data;
# two refs to the same array share one address
say refaddr($a) == refaddr($b) ? "same" : "different";
my $c = [1, 2, 3];
say refaddr($a) == refaddr($c) ? "same" : "different";

refaddr tells same from copy