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From: Robert Dewar <robert_dewar@my-deja.com>
Subject: Re: Bit manipulation
Date: 2000/11/13
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In article <slrn90vl0k.l5.lutz@taranis.iks-jena.de>,
  lutz@iks-jena.de (Lutz Donnerhacke) wrote:

>   pragma Pack(bitfield); -- the following clause will not work
>                          -- without pragma
>   for bitfield'Size use wordsize;

As most certainly you would expect, see RM 13.3:

  53   A Size clause on a composite subtype should not affect
       the internal layout of components.

followed by some gruesome code for doing a rotate, to which
one must ask, why on earth not use the Rotate functions provided
as primitives in Ada 95 (these can be located by looking up
the keyword rotate in the index!)

Yes, I suppose GNAT (or in general any Ada 95 compiler) could
try to optimize this gruesome code, but since no one would
ever write it anyway, why bother?



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