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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: What is the warning about builtin-function on gcc-4.6.0 ?
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Date: Sun, 27 Mar 2011 11:50:45 +0200
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Date: 2011-03-27T11:50:42+02:00
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On Sat, 26 Mar 2011 14:36:04 -0700 (PDT), ytomino wrote:

> On Mar 27, 12:14�am, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
> wrote:

>> When interfacing C, one IMO should always add a range or validity check
>> when taking floating-point values from C, to prevent non-numbers leaking
>> out. Unfortunately it is a lot of work, so no Ada bindings actually follows
>> this rule.
> 
> uh, there are functions (from C) that return infinity/NaN
> intentionally, too.

When a numeric function returns garbage it is useless. When non-numbers are
supposed to serve error indication, they must be converted to an exception,
e.g. Constraint_Error. Which is the whole point. In my view a C binding
should check the result for mess and raise an exception if necessary.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de