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From: Robert A Duff <bobduff@shell01.TheWorld.com>
Newsgroups: comp.lang.ada
Subject: Re: Prohibiting dynamic allocation for the given type
Date: Wed, 19 Mar 2008 20:43:56 -0400
Organization: The World Public Access UNIX, Brookline, MA
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Date: 2008-03-19T20:43:56-04:00
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Maciej Sobczak <see.my.homepage@gmail.com> writes:

> Is it possible to "prohibit" dynamic allocation for the given type?

I don't know of any simple way to do that.

> Let's suppose that I have a type which instances make sense only on
> the stack.

Could you please give some examples of such a type?

Somebody mentioned a lock, which I find only half convincing.
Any others?

>... I want to prohibit users from dynamically allocating
> instances of this type so that they don't get into troubles.
> Preferably at compile-time.
>
> My understanding is that it cannot be done (allocation is not
> considered to be a type's operation and there is no way to "hide" it
> from users - as is possible in C++), but I would like to have it
> confirmed.

Well, you can prohibit clients from creating any objects at all
(heap or stack) by using (<>) discrims, and not exporting any
constructor functions.  But that's not what you asked for.

- Bob