#!/usr/bin/env perl

use 5.010;

package Father;
use Moose;
sub char { lc ref shift }


package Son;
use Moose;
extends 'Father';


package main;
say ref($_) . '->char() = ' . $_->char for new Father, new Son;

##</code><code>##

Father->char() = father
Son->char() = son

##</code><code>##

has 'char'   => (
    is       => 'ro', 
    builder  => '_build_char', # May override _build_char in subclasses
    init_arg => undef,         # Disallow setting via constructor
);
sub _build_char { lc ref shift }

##</code><code>##

use MooseX::Declare;

class Father {
    has char => (
        is       => 'ro',
        builder  => '_build_char',
        init_arg => undef,
    );  
    sub _build_char { lc ref shift }
}   

class Son extends Father { }