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From: Robert A Duff <bobduff@shell01.TheWorld.com>
Newsgroups: comp.lang.ada
Subject: Re: How to get around "access type must not be outside generic unit"
Date: Sun, 17 Dec 2006 15:49:24 -0500
Organization: The World Public Access UNIX, Brookline, MA
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Date: 2006-12-17T15:49:24-05:00
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Michael Erdmann <michael.erdmann@snafu.de> writes:

>>    procedure Register
>>      (Str : in String; A : access function return Boolean);
>> 
> Actually this does not work; compiler complains the anonymous types
> are not allowed here.

It's an Ada 2005 feature.

> private
>    Install_Access : constant Callback_Access := Install'Access;

> But what is the gain of doing it like this. I don't see any
> gain in security..?!

It prevents dangling pointers.  See AI-229.

- Bob