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Date: Wed, 19 May 2004 09:44:24 -0400
From: Hyman Rosen <hyrosen@mail.com>
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Subject: Re: "Must instantiate controlled types at library level." Why?
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Date: 2004-05-19T09:44:24-04:00
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Georg Bauhaus wrote:
> Then what will help an Abstract Datatype? How?

It's Kazakov's post, so you should know the answer by now :-)

He wants ADTs to be implemented using an inherited interface
but to keep the virtual table pointer (or other implementation)
separate from the objects by implementing fat pointers which
combine the address of the object and the address of the vtable.

In this way, he hopes that the code generative power of knowing the
explicit types involved in an operation can combine cleanly with the
expressive power of OO polymorphism. He is both encouraged and
discouraged by the distinction Ada makes between classwide types and
regular types because this comes tantalizingly close to implementing
his vision, unlike in C++ where this is intertwined with parameter
passing semantics of by-reference or by-value.