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From: Ted Dennison <dennison@telepath.com>
Subject: Re: LLQ: -1 a valid boolean?
Date: 2000/05/23
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In article <8gen6a$v72$1@nnrp1.deja.com>,
  Robert Dewar <robert_dewar@my-deja.com> wrote:
> In article <8ge39b$g45$1@nnrp1.deja.com>,
>   Ted Dennison <dennison@telepath.com> wrote:
> > I just ended up doing the following, which looks damn silly
> > (so I had to comment it copiously), but works:
>
> >    if To_Bool_Ptr(Addr).all then
>
> It's not only silly, it is incorrect. There is absolutely NO
> reason to think this should work correctly, since you are
> testing an out of range and hence abnormal value, and the
> result of this test is undefined.

Ahh, that's a different kettle of fish. I thought the verdict was that
this was a valid test, since Boolean'Size is 1, but that assigning it
was wrong becuse Boolean_Object'Size > 1.

So you are saying both are wrong? That's exactly what I was asking
about.

> Writing erroneous code like this and being satisied that it
> happens to work on the particular compiler you are using is
> not a good approach to writing reliable code!

Quite so. The last thing I want is to be called out to timbucktoo for a
week to figure out why part of the simulator fails 6 weeks after they
take a minor compiler upgrade. Worse yet would be to inflict that fate
on some other innocent engineer.

--
T.E.D.

http://www.telepath.com/~dennison/Ted/TED.html


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