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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: The "black magic" of ioctl
Date: Sat, 23 Oct 2010 17:25:49 +0100
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Date: 2010-10-23T17:25:49+01:00
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michael bode <m.g.bode@web.de> writes:

> Am 23.10.2010 14:13, schrieb Simon Wright:
>> michael bode <m.g.bode@web.de> writes:
>> 
>>>       if 0 = Ioctl (Device.Fd, VIDIOC_QUERYCAP, C_Cap'access) then
>> 
>> I recognise the point of this to-me totally counter-intuitive convention
>> in C, really not needed in Ada! (or Python ..)
>
> You mean functions returning error codes? Or putting 0 on the left side
> of the equality operator? Calling C functions from Ada is writing C in
> Ada syntax. Therefore you hide it in a package that looks like Ada to
> the outside.

Putting 0 on the left side of the equality operator to make sure you
don't accidentally make an assignment.