Re: Pure, Storage_Size and Unchecked_Conversion

["Y.Tomino" <demoonlit@panathenaia.halfmoon.jp>]

On Jul 9, 1:08 am, Martin Krischik <krisc...@users.sourceforge.net>
wrote:
> You are aware that this will only work on 32 bit system while 64 bit is the
> future. It does - of course - not mean that you can't do it. You just have
> to do it right.

Don't mind. :-)

> It's one of the definitions of a pure unit: no named access types. It you
> read the Distributed System Annex then you will see why it has to be that
> way.

Thank you. I read it.
I understood access to class wide types is prohibited in remote
packages,
but I could not find description that normal access types were
prohibited (in pure packages).

Actually, Usual functions having access types like F1 are OK.
Generic functions like Ada.Unchecked_Conversion
(or my generic function I tested *1) are disallowed.

What is different ?

*1
generic type T is private; type A is access T;
function G (X : A) return A;
pragma Pure (G); --OK

function G (X : A) return A is begin return X; end G;

with G;
package P is
pragma Pure (P);
type A is access Integer; for A'Storage_Size use 0; --OK
function F1 (X : A) return A; --OK
function F2 is new G (A); --NG
end P;

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