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From: "G.B." <bauhaus@notmyhomepage.invalid>
Newsgroups: comp.lang.ada
Subject: Re: Ada wikibook help needed (O-O)
Date: Mon, 24 Apr 2017 07:13:39 +0200
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Date: 2017-04-24T07:13:39+02:00
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On 23.04.17 19:03, Dmitry A. Kazakov wrote:

> Then,
>
>   "A conversion to the class-wide type makes [components] visible
> again."
>
> Is "visible" correct?

> But, maybe, direct visibility was meant?(...)
>
> If I have "use P" and no "use Q" then conversion to T'Class will make Foo applicable in non-prefix notation.
>
>> Yet, what is meant is that after view conversion, the object can
>> be seen as of any type in T'Class, whichever type it might be.
>
> No, that requires another conversion. To see X as S from T'Class you must convert it to S. T'Class is a substitute for the intersection of all types [values of].


Since we are both trying to learn what was meant, I think this proves
my point ;-).



(Even if the "use" based interpretation does uncover a possible meaning
of the Wikibook, I think a reference to use-visibility here will
drive the reader away from the topic: the question being

   "what happens when a primitive operation Op1 calls another
     primitive operation Op2 ?"

(The example given is not conducive to an interpretations that rests
on use-visibility, I think.)