Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!att!ulysses!andante!alice!shopiro
From: shopiro@alice.UUCP (Jonathan Shopiro)
Newsgroups: comp.lang.c++
Subject: Re: deallocating an array of objects
Summary: Deleting null is harmless
Message-ID: <9517@alice.UUCP>
Date: 21 Jun 89 02:44:19 GMT
References: <2735@ssc-vax.UUCP>
Organization: AT&T Bell Laboratories, Murray Hill NJ
Lines: 45

In article <2735@ssc-vax.UUCP>, dmg@ssc-vax.UUCP (David Geary) writes:
> 
> In article <9500@alice.UUCP>, Jonathan Shopiro writes:
> + In article <1245@cadillac.CAD.MCC.COM>, rpj@redcloud.cad.mcc.com (Rich Johns) writes:
> ...
> + -   for (int i = 0; i < 100; i++) {
> + -     delete fooArray[i];
> + -   }
> 
> + This deletes the pointed-to Foos (and they better be there to delete)
>                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
>   If the pointed-to Foos are not there, and each element of FooArray
> is NULL, will 
> 
> delete fooArray[i];
> 
> do any harm?  I was under the impression that delete, when applied
> to NULL does nothing.

Quite so.  In the original example, they weren't null, they were
uninitialized.

I think it is unfortunate that the language guarantees that delete can
be applied to null harmlessly (the compiler has to generate code to
check for null every time) and I think it is bad form to apply delete
to null pointers.

b
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g

b
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-- 
		Jonathan Shopiro
		AT&T Bell Laboratories, Warren, NJ  07060-0908
		research!shopiro   (201) 580-4229