gistfile1.pl

# see http://gist.github.com/463974

use MooseX::Declare;
use 5.12.0;

if (shift eq 'ujihisa') {
    class Ujihisa {
        method hi {
            'my name is ujihisa'
        }
    }

    *the_klass = sub { 'Ujihisa' }
}
else {
    class Ujm {
        method hi {
            'this is a pen'
        }
    }

    *the_klass = sub { 'Ujm' }
}

say the_klass()->new->hi;