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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: Division by zero
Date: Sun, 12 Jun 2005 18:38:15 +0100
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Date: 2005-06-12T18:38:15+01:00
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Dennis Lee Bieber <wlfraed@ix.netcom.com> writes:

> On Sun, 12 Jun 2005 15:04:17 +1200, "Lurker" <nowhere@nothing.com>
> declaimed the following in comp.lang.ada:
>
>
>> 
>> It was. My question was - should it have been caught
>> at compile time instead?
>>
> 	Possibly not... Isn't 0/0 allowed in IEEE -> giving one of those
> strange NaN type results...

These are integers, though, and GNAT catches integer divide-by-zero.

For floats, you can either check 'Valid (Infs and NaNs aren't) or use
a constrained subtype:

  type My_Float is Float range Float'First .. Float'Last;

which will give you the constraint error you'd expect when you assign
an invalid result to it.  Well, come to think I didn't try with NaN ...