From: "Jeffrey R.Carter" <spam.jrcarter.not@spam.acm.org.not>
Subject: Re: strange cursor in nested containers
Date: Tue, 9 May 2023 10:36:33 +0200 [thread overview]
Message-ID: <u3d0mh$70f5$1@dont-email.me> (raw)
In-Reply-To: <u3cg9c$5ppl$1@dont-email.me>
On 2023-05-09 05:56, Randy Brukardt wrote:
> It's not required to detect such cursors because it is expensive to do so
> perfectly (essentially, each cursor has to be controlled and one has to keep
> a list of them associated with the container). There are imperfect solutions
> which are likely to be "good enough" in practice, but they still have a
> (small) cost which may be an issue for some uses. Thus, most implementers
> don't use them. I know the original GNAT containers had a debugging version
> that included such checks, but I don't know if they still exist or how one
> would enable them if they do.
This cost is due to the decision to allow access to elements using only a
cursor. If both the container and the cursor are needed, then the cost is
significantly reduced. This is the approach that was used in the Ada-95 version
of the PragmAda Reusable Components.
--
Jeff Carter
“Bug rates in C++ are running higher even than C ...”
Stephen F. Zeigler
216
next prev parent reply other threads:[~2023-05-09 8:36 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-19 7:09 strange cursor in nested containers Mario Blunk
2023-04-19 15:07 ` Simon Wright
2023-04-20 5:15 ` Egil H H
2023-04-20 5:33 ` Egil H H
2023-04-20 14:59 ` Simon Wright
2023-04-20 15:28 ` Mario Blunk
2023-04-22 9:33 ` Randy Brukardt
2023-04-22 17:04 ` Mario Blunk
2023-04-22 18:33 ` Jeffrey R.Carter
2023-04-25 7:30 ` Mario Blunk
2023-05-09 3:56 ` Randy Brukardt
2023-05-09 8:36 ` Jeffrey R.Carter [this message]
2023-05-09 8:49 ` Dmitry A. Kazakov
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