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From: robert_dewar@my-dejanews.com
Subject: Re: Alternate to Unchecked_Conversion - Portable?
Date: 1999/02/26
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In article <36d64ce3.10597940@news.pacbell.net>,
  tmoran@bix.com (Tom Moran) wrote:
> >Maybe the Unchecked_Conversion of access types has
> >wider approval from those who develop language
> >standards. There's  RM 13.9(13)  "An implementation may
> >place restrictions on Unchecked_Conversion." to worry
> >about, of course.

Sure, which is why you have to

(a) know what kinds of unchecked conversions you expect
    to be supported

(b) know enough to know what kinds of unchecked conversions
    are in fact almost certain to be supported in all
    implementations. Remember that vendors are interested
    in making your code run, not taking advantage of the
    RM to ensure that your code does NOT run :-)

Also note that there is a big difference between an
instantiation of unchecked conversion that is rejected
at compile time, and an address overlay that is accepted,
but causes mysterious runtime failures, perhaps dependent
on subtle optimization effects!

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