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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Running a preprocessor from GPS?
Date: Fri, 31 Jul 2015 11:13:07 +0200
Organization: cbb software GmbH
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Xref: news.eternal-september.org comp.lang.ada:27258
Date: 2015-07-31T11:13:07+02:00
List-Id: <comp.lang.ada>

On Fri, 31 Jul 2015 09:26:17 +0100, Simon Wright wrote:

> EGarrulo <egarrulo@gmail.com> writes:
> 
>> So far, I only know the "shared/weak pointer" idiom.  If Ada offers
>> something else, besides manual reclamation, I am eager to learn about
>> it.
> 
> Would ref-counted smart pointers suit you? I'd address your problem by
> having a smart pointer to a limited-controlled object representing the
> resource, whose finalization would clean up the resource.

Your pointer is a "hard" (AKA strong) reference/pointer, i.e. the target is
not collected until at least pointer exists.

Soft/weak reference/pointer is a pointer that does not prevent collection,
but itself becomes invalid if collection occurs. [To access the target, a
strong pointer is obtained from the weak pointer, the object is accessed
through it, and then the strong pointer is disposed.]

If there is a complex mesh of references some references must be weak to
prevent circular references:

   O1-->hard-->O2
       <--soft--

Yes, there exist many implementations in Ada *and* there is no reason to
have it in the language, as it can be implemented at the library level.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de