Path: utzoo!attcan!uunet!husc6!mailrus!cwjcc!hal!nic.MR.NET!tank!mimsy!sjr
From: sjr@mimsy.UUCP (Stephen J. Roznowski)
Newsgroups: comp.lang.c
Subject: Re: Passing types to a subroutine
Message-ID: <14548@mimsy.UUCP>
Date: 14 Nov 88 22:55:37 GMT
References: <14457@mimsy.UUCP> <8853@smoke.BRL.MIL>
Reply-To: sjr@mimsy.umd.edu.UUCP (Stephen J. Roznowski)
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 35

In article <8853@smoke.BRL.MIL> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) writes:
>In article <14457@mimsy.UUCP> sjr@mimsy.UUCP (Stephen J. Roznowski) writes:
>>How do you pass the knowledge of the array type to the
>>subroutine?
>
>You don't.  Types are dealt with at compile time, not run time.
>It is in fact possible for a pointer-to-float to be passed
>differently than a pointer-to-double.
>
>If you REALLY have to do this, consider casting the arguments
>(which should be "a", not "a[100]") to type pointer-to-void or
>pointer-to-char, and add another parameter to the subroutine
>that can be used to indicate how to "un-cast" the funny
>parameter.  The code for this won't be clean..

The problem is that I can't determine the array type
at compile time.  These subroutines are going to be part of
a library.

And you are right that the pointers may be different,
or at least have different alignment properties. Is this
true of the pointer-to-void or pointer-to-char?

Stephen

[Let's
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[This is worst than the line eater.]
-- 
Stephen J. Roznowski                 sjr@mimsy.umd.edu