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From: Martin Krischik <martin@krischik.com>
Newsgroups: comp.lang.ada
Subject: Re: Ada equivalent for C-pointer?
Date: Sun, 16 Jan 2005 09:44:21 +0100
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 <gemini.iad8lb0013zf002bc.nick.roberts@acm.org> <u651y3bfs.fsf@obry.net>
 <gemini.iadas3002srzn02bc.nick.roberts@acm.org>
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Date: 2005-01-16T09:44:21+01:00
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Nick Roberts wrote:

> Pascal Obry <pascal@obry.net> wrote:
> 
>> I don't think so. Here Number will be passed by value, no?
> 
> No, I don't think so (with GNAT/GCC).
> 
>> And you also need the returned value ;)
> 
> Yes, oops!
> 
>> So, you probably want:
>> 
>>     function Wibble (Number: access Interfaces.C.int)
>>           return Interfaces.C.int;
>> 
>>     pragma Import(C,Wibble,"wibble");
> 
> I think the 'in out' mode would work with GNAT/GCC, but I'd suggest
> testing it to make sure.

I did the testing - it does work

> I suppose using the 'access' mode might be 
> clearer, and it might be slightly more efficient.

Anonymous access efficient? If you have a copy read John Barnes Ada 95 (2nd
edition), Page 190, 3rd chapter to end of page.

Yes, I know, it does not apply to export/import C functions.

Martin

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