gistfile1.txt

#! /usr/bin/perl

package Foo;
use Moose;
use Test::More;
has foo => ( is => 'rw');
has bar => ( is => 'ro', writer => 'bar' );
has baz => ( is => 'ro', writer => 'set_baz');

my $obj = Foo->new;

$obj->foo;
$obj->foo('test');
is $obj->foo, ('test');

$obj->bar('test');
is $obj->bar, undef;

$obj->set_baz('test');
is $obj->baz, 'test';

$obj->set_baz('foo');
$obj->set_baz;
is $obj->baz, undef;

done_testing;