package Foo;
use Moose;
coerce 'ArrayRef' => from 'Int' => via { [$_] };
has attr => ( is => 'rw', isa => 'ArrayRef[Int]', coerce => 1, );
# ...
1

##</code><code>##

package Bar;
use Moose;
coerce 'ArrayRef' => from 'Int' => via { [$_] };
has another_attr => ( is => 'rw', isa => 'ArrayRef[Int]', coerce => 1, );
# ...
1

##</code><code>##

A coercion action already exists for 'Int' at /usr/lib/perl5/site_perl/5.8.8/Moose/Meta/TypeCoercion.pm line 87