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On Sun, 2007-10-07 at 08:38 +0900, MenTaLguY wrote:
> This is because the requirements of dynamic method dispatch introduce
> additional constraints on subclassing which violate some of the laws a
> simple transitive relationship like "is-a" might reasonably be expected
> to obey.

Actually, I guess this applies to having methods in general.  The
classic ellipse-versus-circle thing is a great example:  "is-a" in the
model domain (shapes) is exactly the opposite from "is-a" in the class
domain, at least in terms of Liskov substitutability.

-mental

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