From: bobduff@world.std.com (Robert A Duff)
Subject: Re: Using a procedure as a parameter (Gnat)
Date: 1996/03/27
Date: 1996-03-27T00:00:00+00:00 [thread overview]
Message-ID: <DowMnK.K6F@world.std.com> (raw)
In-Reply-To: 4ja0da$442@newsflash.concordia.ca
In article <4ja0da$442@newsflash.concordia.ca>,
Chris O'Regan <chris@ECE.Concordia.CA> wrote:
>ack.adb:11:35: subprogram must not be deeper than access type
Deeper means more deeply nested within subprograms (packages don't
count). In your case, you can easily move the procedure into a package,
since it doesn't reference any local variables in the next-outer
procedure. So put P in a library package, and all will be well.
Sometimes, the procedure you want to pass wants to reference variables
in the next-outer procedure. In that case, you can use GNAT's
'Unrestricted_Access. But beware: (1) it's not a standard feature, and
(2) it can cause dangling pointers if you're not careful. A better
alternative might be to use a generic formal subprogram.
- Bob
prev parent reply other threads:[~1996-03-27 0:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
1996-03-26 0:00 Using a procedure as a parameter (Gnat) Chris O'Regan
1996-03-27 0:00 ` Robert A Duff [this message]
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