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From: Robert Dewar <robert_dewar@my-deja.com>
Subject: Re: Enumeration representation
Date: 1999/09/11
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References: <37D8E3BC.175DB72C@newtech.it> <yecn1uu9xy2.fsf@king.cts.com>
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Date: 1999-09-11T00:00:00+00:00
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In article <yecn1uu9xy2.fsf@king.cts.com>,
  Keith Thompson <kst@cts.com> wrote:
  If you try to read
> such a value from an external interface, it's very difficult
> to check that you've gotten a valid value without invoking
> erroneous execution (undefined behavior).

No, it is quite easy, do an unchecked conversion of the value
into the enumeration variable, or just read the value in
directly with appropriate low level I/O, then do a 'Valid test.

And Keith, before you go rummaging around legalise in the RM,
be sure to read the relevant AI, whose purpose is basically
to say, yes of course the above works, whatever the RM says :-)


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