Re: How to use Annex G.3 Vectors and Matrices in bindings to C arrays

["Jerry" <lanceboyle@qwest.net>]

Yves Bailly wrote:
> Jerry wrote:
> > with arrays which are (sub)typed from the Annex G.3 declarations. For
> > example, here is the declaration from the spec of
> > Ada.Numerics.Generic_Real_Arrays which is GNAT file a-ngrear.ads:
>
> Sorry for this off-topic quesiton, but which GNAT version are you using ?
> I just can't find this file in GNAT-GPL...
>
I should have anticipated this. As I understand it, AdaCore has not put
the source for the new vector-matrix packages out yet. (I am using a
4.2 that someone on the MacAda.org site has provided, and the sources
are not in there.) But I found a nearly-complete set of sources here:
    http://www.martin.dowie.btinternet.co.uk/

> Have you tried:
> type A is array(1..10) of Float;
> pragma Convention(C, A);
>
Please see my reply to the next poster. (However, in GNAT, all arrays
are C-compatible, so the use of this pragma is useful only for
compatibility. I _hope_ I've used it, however.)

> The "pragma Convention" might be enough, at least it was when I did
> some OpenGL programming in Ada, passing Ada vectors or matrices to GL
> functions. It worked like a charm.
>