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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Task interface and entries with aliased parameters
Date: Wed, 28 Oct 2015 12:48:05 -0500
Organization: JSA Research & Innovation
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Date: 2015-10-28T12:48:05-05:00
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"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
news:1e09jksdqcfyv.8f80k06gl5ye$.dlg@40tude.net...
> On Wed, 21 Oct 2015 10:01:01 -0700, Jeffrey R. Carter wrote:
>
>> On 10/21/2015 01:54 AM, Hadrien Grasland wrote:
>>>
>>> Using GNAT GPL 2015, I am having some trouble with task interfaces which 
>>> feature entries that take aliased parameters.
>>
>> "IMHO, Interfaces are worthless." -- Randy Brukardt
>
> He possibly meant Java interfaces as opposed to existing Ada 95 abstract
> types. Ada 95 abstract type did everything Java interface do and more.

Yes, precisely. Ada 95 already had a more powerful feature needed to share 
implementations.

Sharing interfaces *sounds* nice, but it's impossible in practice because in 
almost all circumstances you need parameters of different types for 
different "instances" ("instances" not in the Ada sense). Think container 
interfaces, for example - the element type is almost always different.

Interfaces might work in a language where all types are necessarily tagged 
and all derived from a common ancestor, but that language is not at all Ada. 
(And you'd have forced most type checking to runtime, going the wrong way.)

                                      Randy.