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From: Duncan Sands <baldrick@free.fr>
Newsgroups: comp.lang.ada
Subject: Re: C array to Ada pointer to unconstrained array without
	copyingmemory
Date: Fri, 10 Oct 2003 09:02:23 +0200
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Date: 2003-10-10T09:02:23+02:00

> Freeing a fat pointer with unchecked_deallocation is a good question, I
> would guess that it does free correctly. However its any ones guess outside
> of Gnat whether the data is freed in one call or as two. If two I am in
> trouble :)
>
> However, every time i traced the use of these things the bounds were ALWAYS
> immediately before the data in memory, suggesting a single allocation from
> the heap.

Yes, it seems like an obvious optimization: arrays allocated on the heap can have
no address clause, so you can put the bounds with the data if you like, and reduce
the number of memory allocations.  Also, if the bounds are immediately before the
data, doesn't that prove that it was done in one memory allocation, since (IIRC)
malloc reserves some bytes for itself just before a block of memory it allocates, and
GNAT uses malloc?

Ciao,

Duncan.