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From: Ken Garlington <garlingtonke@lmtas.lmco.com>
To: Robert A Duff <bobduff@world.std.com>
Cc: dewar@gnat.com
Subject: Re: Rules for Representation of Subtypes
Date: 1996/10/02
Date: 1996-10-02T00:00:00+00:00	[thread overview]
Message-ID: <3252BAF0.4C3F@lmtas.lmco.com> (raw)
In-Reply-To: DyntAq.6MK@world.std.com


Robert A Duff wrote:
> 
> In article <325155A5.2E50@lmtas.lmco.com>,
> Ken Garlington  <garlingtonke@lmtas.lmco.com> wrote:
> >I seem to remember some AI about using unchecked_conversion when the
> >sizes of X and Y are different. Maybe it's compiler dependent, but I
> >thought you were at least guaranteed that the unchecked_conversion of Y
> >would _fit_ into the space allocated for X, although of course Y might
> >be outside the range of X. In that case, X'Valid should work, shouldn't
> >it?
> 
> No.  See 13.9.1(12).  Nothing, not even 'Valid, can be assumed to work,
> if the execution is erroneous.
> 
> - Bob

So all that discussion in the Ada 83 AI-00590 is wasted when we get to Ada 95?
What a crock!

I'd also say that 13.9.2:1 and 13.9.2:4-12 are very misleading, at best, if
this is the case. It sounds like I would have to write a kludge, wrapping
my scalar inside a record, as the result of my input routine, unchecked conversion,
etc. I hope GNAT and the other compilers raise a warning if I apply 'Valid to
something that is not a record component!

-- 
LMTAS - "Our Brand Means Quality"
For more info, see http://www.lmtas.com or http://www.lmco.com




  reply	other threads:[~1996-10-02  0:00 UTC|newest]

Thread overview: 92+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1996-09-22  0:00 Rules for Representation of Subtypes Matthew Heaney
1996-09-23  0:00 ` Robert A Duff
1996-09-24  0:00   ` Matthew Heaney
1996-09-26  0:00     ` Robert A Duff
1996-09-26  0:00       ` Larry Kilgallen
1996-09-27  0:00         ` Robert A Duff
1996-09-27  0:00           ` Mark A Biggar
1996-09-30  0:00             ` Robert A Duff
1996-10-01  0:00               ` Larry Kilgallen
1996-10-01  0:00                 ` Robert A Duff
1996-10-01  0:00                 ` Samuel Tardieu
1996-10-01  0:00                   ` Valid Attribute and Unchecked Conversion Matthew Heaney
1996-10-02  0:00                     ` Robert A Duff
1996-10-04  0:00                       ` Keith Thompson
1996-10-04  0:00                         ` Robert A Duff
1996-10-04  0:00                           ` Robert Dewar
1996-10-11  0:00                             ` Norman H. Cohen
1996-10-12  0:00                               ` Robert Dewar
1996-10-06  0:00                           ` Keith Thompson
1996-10-07  0:00                             ` Robert Dewar
1996-10-09  0:00                               ` Keith Thompson
1996-10-07  0:00                           ` Ken Garlington
1996-10-08  0:00                           ` Alan Brain
1996-10-04  0:00                         ` Matthew Heaney
1996-10-07  0:00                           ` Robert Dewar
1996-10-09  0:00                             ` Keith Thompson
1996-10-07  0:00                         ` Robert Dewar
1996-10-10  0:00                           ` Ken Garlington
1996-10-11  0:00                             ` Robert Dewar
1996-10-14  0:00                               ` Ken Garlington
1996-10-14  0:00                               ` Keith Thompson
1996-10-07  0:00                         ` Kenneth Almquist
1996-10-01  0:00                   ` Rules for Representation of Subtypes Ken Garlington
1996-09-28  0:00           ` Larry Kilgallen
1996-09-29  0:00             ` Robert A Duff
1996-09-29  0:00               ` Matthew Heaney
1996-09-30  0:00                 ` Robert Dewar
1996-09-30  0:00                   ` Matthew Heaney
1996-09-30  0:00                 ` Robert A Duff
1996-09-29  0:00               ` Larry Kilgallen
1996-09-29  0:00                 ` Matthew Heaney
1996-09-30  0:00                 ` Robert A Duff
1996-10-01  0:00                   ` Ken Garlington
1996-10-02  0:00                     ` Robert A Duff
1996-10-02  0:00                       ` Ken Garlington [this message]
1996-10-06  0:00                   ` Robert Dewar
1996-10-03  0:00             ` Robert Dewar
1996-10-02  0:00         ` Valid Attribute and Unchecked Conversion George Haddad
1996-10-03  0:00           ` John Herro
1996-10-04  0:00             ` Karl Cooper {46901}
1996-10-07  0:00               ` Mark A Biggar
1996-10-08  0:00                 ` Robert Dewar
1996-10-05  0:00             ` Robert Dewar
1996-10-06  0:00               ` Keith Thompson
1996-10-14  0:00                 ` Robert A Duff
1996-10-02  0:00         ` Robert I. Eachus
1996-10-02  0:00           ` Matthew Heaney
1996-09-27  0:00       ` Rules for Representation of Subtypes Matthew Heaney
1996-09-27  0:00         ` Robert A Duff
1996-09-23  0:00 ` David C. Hoos, Sr.
1996-09-23  0:00   ` Robert A Duff
1996-09-23  0:00   ` Samuel T. Harris
1996-09-26  0:00     ` David C. Hoos, Sr.
1996-09-24  0:00   ` Robert Dewar
1996-09-26  0:00     ` Keith Thompson
1996-09-26  0:00       ` Matthew Heaney
1996-09-27  0:00         ` Robert A Duff
1996-09-27  0:00           ` Robert Dewar
1996-09-27  0:00         ` Robert Dewar
1996-09-27  0:00       ` Robert A Duff
1996-09-24  0:00   ` Robert Dewar
  -- strict thread matches above, loose matches on Subject: below --
1996-09-28  0:00 Robert Dewar
1996-09-29  0:00 ` Robert A Duff
1996-09-29  0:00   ` Robert Dewar
1996-09-30  0:00     ` Art Schwarz
1996-09-30  0:00       ` Robert A Duff
1996-10-01  0:00       ` Larry Kilgallen
1996-10-01  0:00         ` Robert A Duff
1996-10-01  0:00         ` Brian R. Hanson
1996-09-29  0:00   ` Matthew Heaney
1996-09-28  0:00 Robert Dewar
1996-09-30  0:00 ` Keith Thompson
1996-09-28  0:00 Robert Dewar
1996-09-29  0:00 ` Robert A Duff
1996-09-29  0:00   ` Matthew Heaney
1996-10-02  0:00 Franco Mazzanti
1996-10-03  0:00 ` Robert A Duff
1996-10-03  0:00 Franco Mazzanti
1996-10-03  0:00 ` Robert A Duff
1996-10-10  0:00 W. Wesley Groleau (Wes)
1996-10-10  0:00 ` Robert Dewar
1996-10-11  0:00 ` Ken Garlington
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