Re: Type extension questions

[comar@cs.nyu.edu (Cyrille Comar)]

koehnema@enuxsa.eas.asu.edu (Harry Koehnemann) writes:
: In article <1995Mar22.125057@di.epfl.ch> Robb.Nebbe@di.epfl.ch (Robb Nebbe) writes:
: >In article <D5tFuE.1vx@ennews.eas.asu.edu>, koehnema@enuxsa.eas.asu.edu (Harry Koehnemann) writes:
: >|> 
: >|> 1) Is it possible to derive a type such that the parent operations are not
: >|>    available to the user of the new type?  This question is equivalent to
: >|>    the ability to do private inheritance ala C++ - class B: private A { ...};
: >|>    I would assume the answer is yes, but haven't yet figured out how.
: >
: >Yes. For example when you need a type to be controlled typically you don't
: >want to expose the finalize, initialize and adjust operations to the client
: >so you write:
: >
: >	package P is
: >
: >	    type T is private;
: >
: >	private
: >
: >	    type T is new Ada.Finalization.Controlled with ...
: >
: >	    procedure Adjust( Object : in out T );
: 
: I don't think my request was clear enough.  This is close, but I'd
: like P.T to be extensible.  The above approach hides the fact that P.T
: is tagged and therefore extensions of P.T are not allowed.  What I
: really want is private inheritance ala C++.
: 
: Thanks for the reply.  Any other suggestions?
: 
: --
: Harry Koehnemann			Arizona State University
: hek@asu.edu				Computer Science Department
-- 
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Cyrille Comar,                                  E-mail: comar@cs.nyu.edu
Gnat Project                                    US phone: (212) 998-3489