From: mheaney@ni.net (Matthew Heaney)
Subject: Re: Fortran's Equivalence
Date: 1997/03/29
Date: 1997-03-29T00:00:00+00:00 [thread overview]
Message-ID: <mheaney-ya023680002903971519450001@news.ni.net> (raw)
In-Reply-To: dewar.859383980@merv
In article <dewar.859383980@merv>, dewar@merv.cs.nyu.edu (Robert Dewar) wrote:
>Vigar says
>
><<
>I have a BIT_PATTERN : System.Unsigned_32. The first 4 bits represent
>an integer A, the next 17 represent another record B, the last eleven
>represent an integer C. Ada gives something beautiful, in the "use at"
>clause, which lets me define a record to superimpose onto the bit
>pattern. The big problem with this approach is that it isn't
>guaranteed by the LRM, and I need my application to be portable to
>other Ada implementations. The Ada Quality and Style Guide, Clause
>5.9.4, also tells us that we should not use the "use at" clause to do
>such things. I am using the GNAT compiler, 3.07 on the SGI. The final
>system will be delivered for a VAX.>>
>
>The statement in the AQ&S is a holdover from Ada 83 days, and I see no
>justification for it. If "use at" does what you want, use it!
This is bad advice Robert. The use of Unchecked_Conversion is clearly what
is required.
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Matthew Heaney
Software Development Consultant
<mailto:matthew_heaney@acm.org>
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next prev parent reply other threads:[~1997-03-29 0:00 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
1997-03-25 0:00 Fortran's Equivalence Viqar Abbasi
1997-03-26 0:00 ` Tom Moran
1997-03-26 0:00 ` Michael F Brenner
1997-03-26 0:00 ` Larry Kilgallen
1997-03-28 0:00 ` Oliver Kellogg
1997-03-29 0:00 ` Matthew Heaney
1997-03-29 0:00 ` Robert Dewar
1997-03-29 0:00 ` Robert Dewar
1997-04-01 0:00 ` Keith Thompson
1997-04-01 0:00 ` Robert Dewar
1997-04-01 0:00 ` Robert A Duff
1997-04-01 0:00 ` Robert Dewar
1997-04-04 0:00 ` Keith Thompson
1997-04-04 0:00 ` Robert Dewar
1997-04-07 0:00 ` Charles H. Sampson
1997-04-07 0:00 ` Keith Thompson
1997-04-07 0:00 ` Viqar Abbasi
1997-04-08 0:00 ` Charles H. Sampson
1997-04-08 0:00 ` Robert Dewar
[not found] ` <1997Apr15.163103.27481@nosc.mil>
1997-04-16 0:00 ` Robert Dewar
1997-04-08 0:00 ` Matthew Heaney
1997-04-09 0:00 ` Stephen Leake
1997-04-09 0:00 ` Robert Dewar
1997-04-10 0:00 ` Simon Wright
1997-04-10 0:00 ` Robert Dewar
1997-04-04 0:00 ` Keith Thompson
1997-04-04 0:00 ` Robert Dewar
1997-04-08 0:00 ` Keith Thompson
1997-04-07 0:00 ` Charles H. Sampson
1997-03-26 0:00 ` Robert Dewar
1997-03-26 0:00 ` Robert A Duff
1997-03-29 0:00 ` Matthew Heaney [this message]
1997-03-29 0:00 ` Robert Dewar
1997-04-02 0:00 ` JP Thornley
1997-03-26 0:00 ` FORTRAN's Equivalence Nick Roberts
1997-03-28 0:00 ` Fortran's Equivalence Charles H. Sampson
1997-03-29 0:00 ` Matthew Heaney
1997-04-01 0:00 ` Charles H. Sampson
1997-03-29 0:00 ` Matthew Heaney
1997-03-29 0:00 ` Robert Dewar
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