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From: Matthew Heaney <matthew_heaney@acm.org>
Subject: Re: System.Address_to_Access_Conversions
Date: 1998/07/26
Message-ID: <m3btqd964p.fsf@mheaney.ni.net>#1/1
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References: <6odddl$k94$1@nnrp1.dejanews.com> <35AB9C59.74E529E0@magic.fr>
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NNTP-Posting-Date: Sat, 25 Jul 1998 17:40:51 PDT
Newsgroups: comp.lang.ada
Date: 1998-07-26T00:00:00+00:00
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nabbasi@earthlink.net writes:

> I read somewhere that the tag position within a record is always defined,
> it is the first element always, right? not sure what's its size, I assume
> it is an address to someother tag related information somewhere else, so its
> size is also known, right?

This is all wrong.  A compiler writer is free to use any implementation
he pleases.

Don't use tagged types to exchange data across an external interface
(unless you're using the DSA).  Use a straight record type, and specify
a representation clause to match the characteristics of the hardware.

Why do programmers like to use tagged types for everything?  Choose the
simplest type for the job, not the most complex.

To paraphrase Robert's comment in a recent post, just because you buy a
super-fancy socket wrench doesn't mean you have to throw away all your
other wrenches!