From: mazzanti@iei.pi.cnr.it (Franco Mazzanti)
Subject: Re: Rules for Representation of Subtypes
Date: 1996/10/03
Date: 1996-10-03T00:00:00+00:00 [thread overview]
Message-ID: <mazzanti-0310961743320001@131.114.200.115> (raw)
Robert A Duff wrote:
> >generic
> > type Source(<>) is limited private;
> > type Target is (<>);
> >function Checked_Scalar_Conversion (S:Source) return Target;
> >
> >
> >with Unchecked_Conversion;
> >function Checked_Scalar_Conversion (S : Source) return Target is
> > type My_Rec is record
> > Scalar : Target;
>
> That's illegal, since Target has unknown discrims. But other than that,
> this approach will work.
>
> But, you don't really need to go to all that trouble. If you just make
> sure your integer types match the hardware (like -2**31..2**31-1 or
> whatever), then unchecked conv of integers will tend to work just fine.
> ...
> ...
>
> - Bob
illegal? isn't Target required to be just a discrete type [RM 12.5.2(2)]?
If I am wrong, is this a GNAT bug (since it compiles without problem)?
Notice that all this trouble might be needed if I want my program to be
as far as possible implementation-independent, or if I want to look for
same mechanically verifiable (as far as possible implementation-independent)
safe coding guidelines (without going to disallow all unchecked conversions).
Franco
next reply other threads:[~1996-10-03 0:00 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
1996-10-03 0:00 Franco Mazzanti [this message]
1996-10-03 0:00 ` Rules for Representation of Subtypes Robert A Duff
-- strict thread matches above, loose matches on Subject: below --
1996-10-10 0:00 W. Wesley Groleau (Wes)
1996-10-10 0:00 ` Robert Dewar
1996-10-11 0:00 ` Ken Garlington
1996-10-02 0:00 Franco Mazzanti
1996-10-03 0:00 ` Robert A Duff
1996-09-28 0:00 Robert Dewar
1996-09-29 0:00 ` Robert A Duff
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
1996-09-29 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 ` Brian R. Hanson
1996-10-01 0:00 ` Robert A Duff
1996-09-22 0:00 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 ` 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 A Duff
1996-09-30 0:00 ` Robert Dewar
1996-09-30 0:00 ` Matthew Heaney
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
1996-10-06 0:00 ` Robert Dewar
1996-10-03 0:00 ` Robert Dewar
1996-09-27 0:00 ` 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
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