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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Ada Successor Language
Date: Tue, 26 Jun 2018 09:44:24 +0200
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Xref: reader02.eternal-september.org comp.lang.ada:53316
Date: 2018-06-26T09:44:24+02:00
List-Id: <comp.lang.ada>

On 2018-06-25 18:21, Dan'l Miller wrote:
> On Monday, June 25, 2018 at 10:19:15 AM UTC-5, Dmitry A. Kazakov wrote:
>> On 2018-06-25 16:44, J-P. Rosen wrote:
>>> Le 25/06/2018 à 16:21, Dmitry A. Kazakov a écrit :
>>
>>>> Ada could allow T'Class for untagged T. T'Class would be an indefinite
>>>> type with values consisting of the actual type's tag and its value. When
>>>> T is by-value type, you pass T'Class to a subprogram as tag + value.
>>>> When T is by-reference type, you pass tag + reference.
>>>>
>>>> Upon dispatch, you strip the tag from the value or reference before
>>>> passing value/reference down.
>>>
>>> It was a requirement of Ada95 that OOP be strictly contained, and that
>>> the same typing system as Ada83 be kept for those who don't want OOP.
>>
>> Don't want OO, don't declare T'Class objects. Where is a problem?
> 
> The problem is that you just proposed 'Class for non-OO semantics.  Your proposal violates the Principal of Least Surprise.

Remember, Ada is a strongly typed language, T'Class is not T, there is 
no way it could break or change anything in T.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de