Re: APQ

[Martin Krischik <martin@krischik.com>]

Dmitry A. Kazakov wrote:

> On Wed, 22 Dec 2004 17:53:14 +0100, Martin Krischik wrote:
> 
>> Dmitry A. Kazakov wrote:
>> 
>>> On Wed, 22 Dec 2004 11:07:44 +0100, Martin Krischik wrote:
>>> 
>>>> Warren W. Gay VE3WWG wrote:
>>>> 
>>>>> I can't imagine it making a practical difference here, but
>>>>> perhaps I lack imagination on this point.
>>>> 
>>>>
>>
http://en.wikibooks.org/wiki/Programming:Ada:Types:access#access_vs._access_all
>>> 
>>> Pool-specific access types do not do well:
>>> 
>>> 1. Upcast/downcast conversions do not work. You'll need
>>> Unchecked_Conversion of pointers. It is nasty and dangerous.
>>> 
>>> 2. '[Unchecked_]Access does not work (otherwise, (1) would be a minor
>>> problem).
>>> 
>>> 3. Rosen's trick does not work. Very bad. Move it to Initialize? That
>>> won't work either, because of 2.
>>> 
>>> 4. Construction/destruction is headache. Wished to insert a newly
>>> created object into a list? Not from Initialize! To delete it from there
>>> upon destruction? Nay!
>>> 
>>> 5. Access discriminants cannot be pool-specific. Converting to general
>>> access to specific one is again an Unchecked_Conversion of worst kind.
>>> 
>>> 6. There is no way to restrict objects allocations to a definite set of
>>> pools. "type X (<>) is ..." does not count.
>>> 
>>> In general, I think that the issue should be thoroughly reworked.
>> 
>> Well, ist wiki. Klick on [edit] and make your point. It OK by me -
>> actually it is he hole point of wiki: incremental impovement.
> 
> Of what? Is wiki =ARG or else [edit button] = AI? (:-))

I thought you mean that the wiki tutorial "Programming:Ada" need some
reworking as it states the disadvantages of Pool-specific access not clear
enough.

As for ARG and the AI - well I guess you know the procedure - if not I can
tell you :-) .

With Regards Martin.

-- 
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