Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!samsung!zaphod.mps.ohio-state.edu!rpi!batcomputer!riley
From: riley@batcomputer.tn.cornell.edu (Daniel S. Riley)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Mutual Exclude Gadgets
Keywords: Gadgets
Message-ID: <9487@batcomputer.tn.cornell.edu>
Date: 31 Dec 89 00:46:10 GMT
References: <947@lpami.wimsey.bc.ca> <22023@usc.edu> <555@shodha.dec.com>
Reply-To: riley@tcgould.tn.cornell.edu (Daniel S. Riley)
Organization: Cornell Theory Center, Cornell University, Ithaca NY
Lines: 24

[for some reason, I just don't believe in email today...]

In article <555@shodha.dec.com> ridder@elvira.enet.dec.com (Hans Ridder) writes:
>Just one question.  What if Commodore adds some stuff to the Gadget
>structure making it larger?  You'd have to re-compile your code with
>new includes, or else their new larger Gadget structure would overlay
>your "extensions".  So really, the *binary* code could possibly not
>work with future releases.  No?

If Commodore changed the size of the Gadget structure, it would break
*every*single*program* which declares its own gadgets.  How many programs
have you seen with initialization expressions like

struct Gadget gidget = { gidget gadget stuff };

hmm?  If Commodore did change the size of the Gadget structure, they
would have to use one of the currently undefined flag bits to indicate
whether this was a fat or skinny gadget structure, and handle skinny
gadget structures like they used to.  Enclosing a gadget structure
inside a structure of your own adds no new constraints or potential
incompatibilities.

-Dan Riley (riley@tcgould.tn.cornell.edu, cornell!batcomputer!riley)
-Wilson Lab, Cornell University