From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,f76dd8b9e12e409a
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-05-09 09:54:59 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!canoe.uoregon.edu!hammer.uoregon.edu!skates!not-for-mail
From: Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov>
Newsgroups: comp.lang.ada
Subject: Re: Access to subprogram
Date: 07 May 2002 12:16:22 -0400
Organization: NASA Goddard Space Flight Center (skates.gsfc.nasa.gov)
Message-ID: <uy9ew53xl.fsf@gsfc.nasa.gov>
References: <ab8i70$rgb$1@newstoo.ericsson.se>
 <mailman.1020776522.17239.comp.lang.ada@ada.eu.org>
NNTP-Posting-Host: anarres.gsfc.nasa.gov
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Trace: skates.gsfc.nasa.gov 1020788579 23393 128.183.220.71 (7 May 2002
 16:22:59 GMT)
X-Complaints-To: usenet@news.gsfc.nasa.gov
NNTP-Posting-Date: 7 May 2002 16:22:59 GMT
User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2
Xref: archiver1.google.com comp.lang.ada:23783
Date: 2002-05-07T16:22:59+00:00
List-Id: <comp.lang.ada>

"David C. Hoos" <david.c.hoos.sr@ada95.com> writes:

> From: "Sebastian" <sebastian.madunic@avionics.saab.se>
> > What is the meaning of this
> > " subprogram must not be deeper than access type"
> It means exactly what it says.  You're trying to take the access
> value of a subprogram that is nested more deeply than is the
> place where the access type is declared.
> 
> To remedy this, you need to do one of two things, viz.:
> 
>    1.  Declare the subprogram at library level -- i.e., not in
>         a package or nested within another subprogram
> 
>    2.  Use 'Unrestricted_Access instead of 'Access, if you're
>         using GNAT, and if your are certain that the lifetime of
>         the subprogram is at least as long as the lifetime of the
>         access type.

Rule 2 is actually too restrictive. You can use Unrestricted_Access if
you are sure that the lifetime of the program is at least as long as
that of all copies of the access value. The compiler assumes copies of
the access value can last as long as the access type, but you don't
have to.

-- 
-- Stephe