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From: "Beard, Frank" <beardf@spawar.navy.mil>
Newsgroups: comp.lang.ada
Subject: RE: Ada 0y wish list: "with private"
Date: Thu, 15 Feb 2001 14:16:52 -0500
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Date: 2001-02-15T14:16:52-05:00

I disagree.  If the compiler treated the deferred type
as a "by reference" type then there wouldn't be a problem.
It would be similar to an access type without the requirement
of allocation/deallocation, null checks, etc.

When a variable of type B is declared, the compiler will
always pass it by reference (by address), which is the
equivalent of passing an access type.

Frank

-----Original Message-----
From: Christoph Grein [mailto:christoph.grein@eurocopter.de]
Sent: Wednesday, February 14, 2001 11:54 PM
To: comp.lang.ada@ada.eu.org
Subject: RE: Ada 0y wish list: "with private"


   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.