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From: Christoph Grein <christoph.grein@eurocopter.de>
Newsgroups: comp.lang.ada
Subject: RE: Ada 0y wish list: "with private"
Date: Thu, 15 Feb 2001 05:53:53 +0100 (MET)
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Date: 2001-02-15T05:53:53+01:00

   package A is

      type B is private;

   private

   end A;

   package body A is

      type B is ...;

   end A;

There are severe code generation problem with this proposal. When the spec of A 
is compiled, the compiler has to know how big objects of type B are. So the full 
declaration has to go into the spec.

   package A is

      type B is private;

   private

      type X;
      type B is access X;

   end A;

   package body A is

      type X is ...;

   end A;

With this solution, it's definitely clear how big B is, irrespective of the size 
of X;