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From: "Wade Humeniuk" <humen...@cadvision.com>
Newsgroups: comp.lang.lisp
Subject: Re: Preventing a class from being instantiated
Date: Wed, 28 Nov 2001 22:17:06 -0700
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>
> That will not work, because the method will also be called for
> instances of subclasses.
>

Yah, you are right.

> You probably want to define an eql-method on make-instance instead:
>
> (defmethod make-instance
>     ((class (eql (find-class 'forbidden-abstract-class))) &rest initargs)
>   (error "Cannot Instatiate Abstract Class"))

This is better because the error is signalled before much CLOS machinery
gets executed.

Wade