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From: dhunter@interserf.net (David Hunter)
Subject: Question about tagged types and functions
Date: 1996/05/21
Message-ID: <4ntg05$qgc@ns.interserf.net>#1/1
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organization: Internet Services Of Fredericksburg
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newsgroups: comp.lang.ada
Date: 1996-05-21T00:00:00+00:00
List-Id: <comp.lang.ada>


Given:

  package Test is

    type BaseType is tagged record
      null;
    end BaseType;

    function Create return BaseType;

    type DerivedType is new BaseType with record
      null;
    end DerivedType;

  end Test;

Why does Ada-95 (GNAT 3.01a) tell me that I also
*must* have:

    function Create return DerivedType;

There is something going on with tagged types
and functions that I don't understand because
if I use

    procedure Create(a : out BaseType);

it (Ada-95) does not object.

===============================================
David Hunter (hunter@mwc.edu)
CPSC Department
Mary Washington College
Fredericksburg, VA 22401