Re: Access to array slices?

["Warren W. Gay VE3WWG" <ve3wwg@cogeco.ca>]

Wojtek Narczynski wrote:
...snip...
> When it comes to network byte order, this is a good thing:
> 
> http://www.ibpaus.de/downloads/AdaStreamsInNetworkByteOrder_020326.tar.gz
> 
> I think that GNAT using this is still compatible with RM, because byte
> order for streams is not defined there. Correct?

Depending upon the hosts used, this would appear to work
fine. However, there is one warning I would like to suggest
is worth looking into:

The GNAT network byte ordering scheme only performs byte swapping
based upon big/little endian machines. This raises two possible
issues (one of which you can probably ignore):

   1. The byte swapping method only works if machines at each
      end use the SAME FLOATING POINT REPRESENTATION. I believe
      most modern architectures do, but I know that the XDR
      routines (for RPC under UNIX), went out of their way to
      specify what the network floating point representation
      should be. This can be different than what is actually
      used on a particular local host (endian change or not).

   2. Hopefully this no longer applies, but some of the old
      iron out there (PDP?) swapped words and bytes in
      conflicting order (words were big endian and bytes
      within the word were little endian (or maybe I got it
      backwards).  If this is the case, the little/big
      endian conversions will simply not work. But you can
      probably ignore this issue today ;-)

wwg.
-- 
Warren W. Gay VE3WWG
http://home.cogeco.ca/~ve3wwg