From mboxrd@z Thu Jan  1 00:00:00 1970
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From: Robert A Duff <bobduff@world.std.com>
Subject: Re: Can't export object of private type
Date: 1999/03/03
Message-ID: <wcc678ia2kk.fsf@world.std.com>#1/1
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Sender: bobduff@world.std.com (Robert A Duff)
References: <7b8cvc$ii5$3@plug.news.pipex.net> <F7w5zn.G7z@syd.csa.com.au>
Organization: The World Public Access UNIX, Brookline, MA
Newsgroups: comp.lang.ada
Date: 1999-03-03T00:00:00+00:00
List-Id: <comp.lang.ada>

nospam@thanks.com.au (Don Harrison) writes:

> Since Planet_Id is exported, anyone can declare an object of that type. 
> We want to ensure there is only a single instance shared by all clients.

If you want a package to have control over object allocation,
export a type with unknown discriminants.  Then clients can't
create objects.  The package itself is the only thing that can
create objects, and so it can place whatever restrictions it
likes, in your case, just one.

- Bob
-- 
Change robert to bob to get my real email address.  Sorry.