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=unavailable autolearn_force=no version=3.4.4
Path: 
 buffer2.nntp.dca1.giganews.com!border2.nntp.dca1.giganews.com!nntp.giganews.com!newspeer1.nac.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.fsmpi.rwth-aachen.de!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: Trying to understand Ada.Finalization.Controlled assignment
 mechanics.
Date: Tue, 23 Sep 2014 10:50:11 -0700
Organization: Also freenews.netfront.net; news.tornevall.net;
 news.eternal-september.org
Message-ID: <lvsbsj$5f0$1@dont-email.me>
References: <024b1649-e056-4b7a-9072-7c7ef0c53f0b@googlegroups.com>
 <lvqhmp$rbc$1@dont-email.me>
 <c00f67d3-3653-43c5-bdf3-c2140f8c5fd9@googlegroups.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Injection-Date: Tue, 23 Sep 2014 17:50:13 +0000 (UTC)
Injection-Info: mx05.eternal-september.org;
 posting-host="ff2e5d21b9fb0a12a9871c15f1d89f02";
 logging-data="5600"; mail-complaints-to="abuse@eternal-september.org";
 posting-account="U2FsdGVkX18VQt0kxq9CMYDmFybAtQ4WWFX6HyCPTwg="
User-Agent: Mozilla/5.0 (X11; Linux x86_64;
 rv:31.0) Gecko/20100101 Thunderbird/31.1.0
In-Reply-To: <c00f67d3-3653-43c5-bdf3-c2140f8c5fd9@googlegroups.com>
Cancel-Lock: sha1:HEgFEGhXv+qv1Te2Hjsr27blTlY=
Xref: number.nntp.dca.giganews.com comp.lang.ada:189108
Date: 2014-09-23T10:50:11-07:00
List-Id: <comp.lang.ada>

On 09/23/2014 09:08 AM, Jeremiah wrote:
> 
> I previously thought:
> A := B
> Finalize(A)
> copying B into A
> Adjust(B)

I must have misread that. Adjust is always called on the target of assignment (A
in this case). As Beneschan pointed out, B could be constant.

> But in reality it is closer to:
> Finalize(A)
> copying B into A
> Adjust(A)

In the case where the anonymous temporary is optimized away, this is what happens.

-- 
Jeff Carter
"All citizens will be required to change their underwear
every half hour. Underwear will be worn on the outside,
so we can check."
Bananas
29