From -2998852370894894047
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: f78e5,e94695845965b249
X-Google-Attributes: gidf78e5,public
X-Google-ArrivalTime: 1992-12-19 15:59:34 PST
Newsgroups: comp.std.c++
Path: sparky!uunet!zaphod.mps.ohio-state.edu!cs.utexas.edu!torn!nott!bnrgate!bcrka451!bcrki65!sjm
From: sjm@bcrki65.bnr.ca (Stuart MacMartin)
Subject: Re: Zero-length structures and pointer comparisons
Message-ID: <1992Dec18.202535.2393@bcrka451.bnr.ca>
Sender: 5E00 Corkstown News Server
Organization: Bell-Northern Research Ltd., Ottawa, Canada
References: <1992Dec14.225659.24225@microsoft.com> <9235215.11144@mulga.cs.mu.OZ.AU> <1992Dec17.230520.13836@microsoft.com>
Date: Fri, 18 Dec 1992 20:25:35 GMT
Lines: 17

In article <1992Dec17.230520.13836@microsoft.com> jimad@microsoft.com (Jim Adcock) writes:
>Granted that an inverse mapping can
>give you the obid from the pointer, its just that such would typically
>be very slow compared to the address comparisons you expect.  Slower
>than using surrogates for example.  So why not use surrogates?

Not to mention the fact that some of us feel that the object id should
be private information of the OODBMS.  I would not like a specification
that effectively required the oid to escape into the application.
If I were an OODBMS developer, I might then be tempted to have 2 oids
per object, one for references and the other for ordering.

Stuart
--
: Stuart MacMartin                                    email: sjm@bnr.ca      :
: Bell-Northern Research                              phone: (613) 763-5625  :
: PO Box 3511, Stn C, Ottawa, K1Y-4H7, CANADA    Standard disclaimers apply. :