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Path: utzoo!linus!philabs!pwa-b!mmintl!franka
From: franka@mmintl.UUCP (Frank Adams)
Newsgroups: net.lang.c
Subject: Re: c types problem
Message-ID: <1008@mmintl.UUCP>
Date: Tue, 7-Jan-86 11:04:07 EST
Article-I.D.: mmintl.1008
Posted: Tue Jan  7 11:04:07 1986
Date-Received: Sat, 11-Jan-86 06:00:20 EST
References: <870@kuling.UUCP> <1261@brl-tgr.ARPA>
Reply-To: franka@mmintl.UUCP (Frank Adams)
Organization: Multimate International, E. Hartford, CT
Lines: 21

In article <1261@brl-tgr.ARPA> gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) writes:
>> I need to define a type for a program which can store any of the types
>> long, int, short and also the unsigned variants of them.
>> Some of the routines referencing this types will not use them directly
>> however, it will use the sys/types.h typedefs dev_t, time_t etc.
>> It will look something like this: "(*func)(&data)" there *func,
>> but not the calling routine knows what type is currently stored in "data".
>> The formal (but ugly) way to solve this would proparbly be to use a union
>> for all (about 10) types. But now I wonder if anyone have a simpler but
>> resonably portable solution?
>
>Since you're going to pass pointers, just coerce the actual data
>address into a generic pointer ((void *) if you have it, otherwise
>(char *)) and coerce it back inside the called function.

I got the impression he wanted long, short, etc. in his union, as well as
pointers.  If so, I don't think (void *) is portable; a long is bigger than
any pointer on some machines.

Frank Adams                           ihpn4!philabs!pwa-b!mmintl!franka
Multimate International    52 Oakland Ave North    E. Hartford, CT 06108