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From: Justin Gombos <rpbkbq.xax.gld@uluv.kbq>
Subject: Re: private types
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Date: Fri, 17 Mar 2006 23:44:08 GMT
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Date: 2006-03-17T23:44:08+00:00
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On 2006-03-17, Robert A Duff <bobduff@shell01.TheWorld.com> wrote:
> Justin Gombos <rpbkbq.xax.gld@uluv.kbq> writes:
>
> I'm not sure what the right answer is, but surely all the arguments
> for and against dummy values apply equally to access types.

I don't agree with that.  Null is a standard abnormal object for
access types in all languages, and can never be taken for something
valid.  Null pointers are quickly detected, and easily understood.

But with any other type, null (zero) is most likely a valid value.
This is probably why the ARM states:

      The implicit initial value for an access subtype is the null
      value of the access type.

But makes no such rule for other types.

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