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From: emery@MITRE-BEDFORD.ARPA (Emery)
Newsgroups: comp.lang.ada
Subject: re: renaming types
Message-ID: <8706291307.AA02368@mitre-bedford.ARPA>
Date: Mon, 29-Jun-87 09:07:01 EDT
Article-I.D.: mitre-be.8706291307.AA02368
Posted: Mon Jun 29 09:07:01 1987
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besides the two possible solutions (record with single component, and access),
there's a third possibility:


    package A is
      type T is private
    private
      type T is new B.BT;
    end A;

However, this introduces all the 'overhead' of derived types.  I've often wanted
to complete a private type definition as simply another type, so I think this
is a real problem, since several people (independently) have identified this
shortcoming (see the ACM SIGAda Language Issues WG discussions on this topic).

However, I'm not sure that 'rename' is the right operation.  It seems to me
that 'subtype' may be even better:

  package A is
    type T is private;
  private 
    subtype T is new B.BT;	-- possibly constrained, too!
  end A;

				dave emery
				emery@mitre-bedford.arpa