Re: Ada is getting more popular!

[ramon_garcia <ramon.garcia.f@gmail.com>]

On Oct 14, 12:34 am, "Vinzent Hoefler" <nntp-2010...@t-
domaingrabbing.de> wrote:
> Huh? Since when do "out" parameters imply a copy?

If the size is determinated at runtime, the caller cannot know the
size in advance, and cannot allocate it. In fact, GNAT has a
"secondary stack" for returning variable-size objects.

> I don't understand that. Either you are creating the array
> dynamically, then getting an access to it should not be a problem
> or the caller already knows the bounds.

The array was created statically, but I do not want code in the caller
to depend on that.

Or a container record was created dynamically, and the size of the
array is part of the discriminant.

type container(n_elemen: natural) is record
     a: buffer(n_elemen);
end record;

Imagine that this type is defined in the private part of the package.
A method is provided to obtain an access to the buffer, and from that
access the bounds of the array can be obtained at run time. This is
not posible in general.