An example of Moo.

moo_sample.pl

#!/usr/bin/env perl

package MooSample;

use Moo;
use MooX::Types::MooseLike::Base qw(:all);

has 'val_int' => (
    is => 'ro',
    isa => Int,
);

has 'val_bol' => (
    is => 'ro',
    isa => Bool,
);

has 'val_str' => (
    is => 'ro',
    isa => Str,
);

1;

package main;

use Devel::Dwarn;

my $obj = MooSample->new(
    val_int => 1,
    val_bol => 1,
    val_str => "testtest",
);

$obj->$::Dwarn; # The dump method is not provided by default.

exit;