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From: Robert Dewar <robert_dewar@my-deja.com>
Subject: Re: Type mess in Ada standard library
Date: 1999/07/21
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References: <7n1uu4$so8$1@pegasus.csx.cam.ac.uk> <7n32tt$cio$1@nnrp1.deja.com>
 <7n41v3$j6$1@pegasus.csx.cam.ac.uk>
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Date: 1999-07-21T00:00:00+00:00
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In article <7n41v3$j6$1@pegasus.csx.cam.ac.uk>,
  mgk25@cl.cam.ac.uk (Markus Kuhn) wrote:
> Robert Dewar <robert_dewar@my-deja.com> writes:
> |> I would have liked to see an attribute, call it for now
> |>
> |>   typ'Anonymous_Access

Just to be clear I would ONLY allow this in subprogram formals,
and I would be quite happy to restrict it to those which had
foreign conventions, otherwise I am afraid it would be horribly
overused.

> That sounds like a very good idea to me, and adding this in
> GNAT would certainly be a valuable contribution.

I am not so sure, I am afraid it would be misused

> Would it at the same time also be possible to add anonymous
> arrays?
>
>   typ'Array(0..255,0..255)  -- anonymous 64k 2D array of typ
>   typ'Array(<>,<>,<>)       -- any 3D array of typ

In fact it is *exactly* this question that makes me think that
it is a bad idea to introduce the anonymous access type. If
people simply think of this as a way to weaken typing (as in
the above array proposal), rather than as a way to solve a
particular problem in genericity at the interfacing level, I
am afraid that such features can do more harm than good.


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