Re: Unchecked_Deallocation subtleties

["Marin David Condic" <mcondic.auntie.spam@acm.org>]

Samuel Tardieu <sam@rfc1149.net> wrote in message
news:873ckr979l.fsf@inf.enst.fr...
>
> I agree, but the RM deliberately ignores such a factor. Otherwise, no
> function would ever be Pure in the RM sense, as the omission of the
> call would never yield the same "result".
>
Obviously, as a language standard, it must for the most part ignore time. It
can't account for how something gets implemented, so trying to address time
becomes problematic. In probably 99.9% of the applications, time doesn't
matter, so if a function takes more or less time dealing with the
off-nominal case, nobody much cares. But put that call in a selective wait
with a delay alternative and suddenly you might see different program
behavior if the off-nominal case changes the timing.

I just brought it up as a reminder that "no effect" from the ARM perspective
is not equivalent to "no observable difference in the real world". The ARM
concern is that there be no semantic effect. A call to a deallocate routine
with a null pointer might cause the rectal extraction of several flying
monkeys, but so long as the program continues to compute what the ARM
expects, its happy. :-)

MDC
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Marin David Condic
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