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From: Ivan Levashew <octagram@bluebottle.com>
Newsgroups: comp.lang.ada
Subject: Re: Interfaces and abstract tagged types
Date: Thu, 16 Oct 2008 00:51:53 -0700 (PDT)
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>
> >> (Interfaces was a huge mistake)
>
> > Interesting. =A0Why do you say so?
>
> Because there already existed abstract types for
> that. One should simply
> have allowed honest multiple inheritance.
>
> The limitation of not having any implementations of
> primitive operations or
> component makes just no sense.

I'm wondering why nobody has replied yet.

I think it to be a known thing. Interfaces are by definition
implementation-less. A bindable implementation of interface is called
adaptor. In Ada 2005, adaptors are mapped to generic mix-ins.

See Case 2 here:
http://www.adaic.org/learn/tech/multin.html

The only difference with Ada 2005 is that mix-ins were unable to be
adaptors in Ada 95 (there was no interfaces).