Re: Unchecked_Deallocation subtleties

["Warren W. Gay VE3WWG" <ve3wwg@cogeco.ca>]

Marin David Condic wrote:
> Samuel Tardieu <sam@rfc1149.net> wrote in message
> news:87smssj94u.fsf@inf.enst.fr...
> 
>>"no effect" means "no user observable effect". Just as if you didn't
>>call "Free(X)". If "Deallocate" may have side effects, it should not
>>be called.
>>
> 
> No side effect other than possibly execution time. I don't believe the ARM
> considers execution time to to be a factor in determining if there is "no
> effect" - but obviously, in some applications, that might be an issue.
> 
> MDC
> --
> ======================================================================
> Marin David Condic
> I work for: http://www.belcan.com/

I have always believed that this type of "permissiveness" is bad. If
the caller knew in advance that there was nothing to free, then Free(X)
would never be called in the first place. To me, this (when X is null)
should raise an exception since it represents an unintended operation or
state of the access type.

It appears that a concession has been made to lazy programmers so that
they can avoid the necessary if statements, such as:

if X /= null then
    Free(X);
end if;

This issue must have been hotly debated at one time or another (and
perhaps re-occuringly so).  Of course, you can always insist on a
different behaviour, by including a wrapper routine in your application
(but I still would have preferred the other "default").

-- 
Warren W. Gay VE3WWG
http://home.cogeco.ca/~ve3wwg