It seems like your subclassing confusion got sorted out. Here is a snippet for 'required' arguments to constructors, using Class::MakeMethods. Check out the Examples about custom initialization for more ideas

package Foo;

use Class::MakeMethods::Template::Hash (
  'new --with_init' => 'new',
  scalar => 'foo',
);

sub init {
  my $self = shift;
  my %args = @_;
  die 'I need foo!' unless $args{ foo };
  $self->foo( $args{foo} );
}
[download]

Basically the constructor hands off value initialization to an init method if asked to. It may be that Class::MethodMaker supports this kind of thing too - I'm not familiar with it.

qq