Re: Questions

[Robert A Duff <bobduff@shell01.TheWorld.com>]

"Nick Roberts" <nickroberts@blueyonder.co.uk> writes:

> "Robert A Duff" <bobduff@shell01.TheWorld.com> wrote in message
> news:wcc7k9mi4rb.fsf@shell01.TheWorld.com...
> 
> > Jakub Zawadzki <darkjames@poczta.onet.pl> writes:
> >
> > > It's guestions from my friend
> > > Emaix>I have a question. Does a String(1..X) occupy X bytes always, no
> > > Emaix> matter what actual length the string has got?
> >
> > Heh?  The length of the string *is* X.  So yes, it occupies X bytes
> > (plus whatever dope is necessary).
> 
> Sometimes a srting such as, for example, defined by String(1..10), will
> occupy 20 or 40 bytes (plus 'dope information'), unless pragma Pack is
> applied to it. This is because normally the compiler will allocate one
> 'storage element' per character (so as to maximise speed of access to it)
> and on some target machines storage elements are 16 or 32 bits in size.
> (Some unusual machines have other sizes of storage element.)

First, I'm willing to bet that the OP is not interested in such
machines.

Second, pragma Pack applies to type String, in all implementations of
Ada, and the requirements on Pack mean 4-chars-per-word on a
32-bit-word-addressable machine.

I think you (Nick) and I have both missed what the OP is getting at.
Perhaps he should clarify the question, perhaps with an example that
illustrates the point...

- Bob