use strict;
use warnings;
use 5.012;

package Point;
use Moose; # automatically turns on strict and warnings

has 'x' => (is => 'rw', isa => 'Int');
has 'y' => (is => 'rw', isa => 'Int');

############

my $p = Point->new(10, 20);

say $p->x;
say $p->y;

--output:--
Use of uninitialized value in say at 2.pl line 44.

Use of uninitialized value in say at 2.pl line 45.