Path: utzoo!mnetor!uunet!husc6!necntc!ima!haddock!karl
From: karl@haddock.ISC.COM (Karl Heuer)
Newsgroups: comp.lang.c
Subject: Re: While talking about useful additions, how about this one??
Message-ID: <2528@haddock.ISC.COM>
Date: 9 Feb 88 21:50:52 GMT
References: <253@vsi1.UUCP> <127@ghostwheel.UUCP> <7169@brl-smoke.ARPA> <131@ghostwheel.UUCP>
Reply-To: karl@haddock.ima.isc.com (Karl Heuer)
Organization: Interactive Systems, Boston
Lines: 22
Summary: "struct *" can be done with existing constructs

In article <131@ghostwheel.UUCP> ned@ghostwheel.aca.mcc.com.UUCP (Ned Nowotny) writes:
>[Re "struct *" for a generic pointer to a structure]
>I don't want to mix pointers to different structure types, but I do want
>to write generic code which manipulates complex objects (e.g. linked list
>managers).

How about writing "struct generic *", where "struct generic" is never defined?
This is already syntactically and semantically legal.

>As a rational, consider that given "int a, b;", "int *a_ptr;" declares a
>pointer which may freely point to either "a" or "b"

Yes; so "int *" is a pointer to any int.  But it can't point to a short int or
a long int.  The analogy is pretty weak, I'd say.

>In fact, given: "typedef int a_int; typedef int b_int;" [both cc and lint
>allow mixing of the two types].

That's because typedef creates a new name for an existing type, rather than a
new type.  You want dimensional analysis?  I'm working on it.

Karl W. Z. Heuer (ima!haddock!karl or karl@haddock.isc.com), The Walking Lint