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From: lutz@iks-jena.de (Lutz Donnerhacke)
Newsgroups: comp.lang.ada
Subject: Re: Sugestion to Multiple Inheritance
Date: Fri, 11 Jan 2002 17:53:29 +0000 (UTC)
Organization: IKS GmbH Jena
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* Stephen Leake wrote:
>lutz@iks-jena.de (Lutz Donnerhacke) writes:
>>      A -> B     B is an extended A and C is an extended A.
>>      |    |     D combines both extensions (requiring both).
>>      v    v
>>      C -> D
>
>I need more information about why C and B need to be independent types.

They do not need to be types at all. They are abstactions => interfaces.
Example: A describes a sort algorithm. B describes stableness. C describes
in-place-ness. D describes stable, in-place sort algorithms.

The problem becomes worse if more attributes are required.

Planned usage:

   generic
      ....  Stable_Sort ...;
   package
      ...
   end package;

If I define a implementation of D, I'd like to use is in contexts where A,
B, or C is required as well.

>Basically, you've drawn a diagram that can't be implmented in Ada, and
>asked how to implement it.

Ack. And I offered some solutions. I won't complain about a missing feature.

>The only solution is to give more information about the real problem, so
>we can suggest how to modify the diagram so it can be implemented.

HTH.