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From: Hyman Rosen <hymie@prolifics.com>
Subject: Re: Announce: OpenToken 2.0 released
Date: 2000/02/02
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Brian Rogoff <bpr@shell5.ba.best.com> writes:
> True, though the high falutin thing is more general and much less prone to 
> error since it expresses the intent clearly. Its also easily expressible
> in C++ (your favorite language?) and other languages which have some form
> of parametric polymorphism and variant types. I suppose you can do it in
> Eiffel too but faking variants (tagged unions) with classes is an extra
> level of ugliness IMO. 

Yup (C++). I've seen it referred to as "Fallible<T>". I've also seen
an amusing variant which forces you to test error return codes from
functions. The function returns a "MustRead<T>" object, which will
throw an exception if it is destructed before the value it holds is
extracted.