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From: Florian Weimer <fw@deneb.enyo.de>
Subject: Re: Does a null pointer always raise Constraint_Error?
Date: 13 Dec 2000 21:07:01 +0100
Date: 2000-12-13T21:07:01+01:00	[thread overview]
Message-ID: <87zoi0w0ey.fsf@deneb.enyo.de> (raw)
In-Reply-To: 9185a6$mut$1@nnrp1.deja.com

Robert Dewar <robert_dewar@my-deja.com> writes:

> > There a two language-defined checks involved prior
> > to the array comparison.  However, 11.6(5) seems to
> > permit the omission of these checks, but I'm not
> > sure about that.
> 
> Nobody is sure about 11.6 :-)

:-)

> I don't think it applies however. Why not? Because
> the program does indeed depend on the result of this
> comparison. If you did
> 
>   Junk := a.all = b.all;
> 
> and never referenced junk, then you could use
> 11.6(5) to argue that the check should be omitted.

That's one of the simple cases everybody seems to be happy with.

I would argue that a.all and b.all are undefined, but because of their
type, their values can be compared with a well-defined result anyway.



  reply	other threads:[~2000-12-13 20:07 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <Pine.LNX.4.10.10011301306120.793-100000@lexis.di.fct.unl.pt>
     [not found] ` <tgzoihpon4.fsf@mercury.rus.uni-stuttgart.de>
     [not found]   ` <9074fi$93b$1@nnrp1.deja.com>
     [not found]     ` <3A3253B1.AD8F32CF@ebox.tninet.se>
     [not found]       ` <90u1vi$uah$1@nnrp1.deja.com>
     [not found]         ` <90ukfm$c4p$1@nnrp1.deja.com>
2000-12-12 16:23           ` Does a null pointer always raise Constraint_Error? Wayne Magor
2000-12-12 20:27             ` Keith Thompson
2000-12-13  0:46               ` Robert Dewar
2000-12-13  8:58                 ` Lutz Donnerhacke
2000-12-13 13:56                   ` Ken Garlington
2000-12-13 14:25                     ` Lutz Donnerhacke
2000-12-13 14:58                       ` Florian Weimer
2000-12-13 15:17                         ` Lutz Donnerhacke
2000-12-13 15:40                         ` Robert Dewar
2000-12-13 20:07                           ` Florian Weimer [this message]
2000-12-14 13:08                             ` Robert Dewar
2000-12-14 14:29                               ` Ken Garlington
2000-12-15  1:45                                 ` Robert Dewar
2000-12-13 15:37                       ` Robert Dewar
2000-12-12 20:31             ` Keith Thompson
2000-12-13 19:58               ` Florian Weimer
2000-12-13  0:43             ` Robert Dewar
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