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,f51e93dacd9c7fca
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-06-19 05:40:09 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news.tele.dk!small.news.tele.dk!130.133.1.3!fu-berlin.de!uni-berlin.de!tar-alcarin.cbb-automation.DE!not-for-mail
From: Dmitry A. Kazakov <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: status of Ada STL?
Date: Wed, 19 Jun 2002 14:45:34 +0200
Message-ID: <ltu0huchrmmjkabapv55qjrrv1firg9gpi@4ax.com>
References: <bebbba07.0206132321.23d72ac8@posting.google.com>
 <aedgoc$to7$1@news.iucc.ac.il>
 <bebbba07.0206151051.1c25cf1e@posting.google.com> <uu1o31wbb.fsf@wanadoo.fr>
 <bebbba07.0206161023.6073fd3a@posting.google.com>
 <3d0ce154_5@news.bluewin.ch>
 <bebbba07.0206162120.3acf4278@posting.google.com>
 <3d0e574d_2@news.bluewin.ch> <wccelf4zkxk.fsf@shell01.TheWorld.com>
 <3d0fb5e8$1_3@news.bluewin.ch>
NNTP-Posting-Host: tar-alcarin.cbb-automation.de (212.79.194.111)
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Trace: fu-berlin.de 1024490406 9578731 212.79.194.111 (16 [77047])
X-Newsreader: Forte Agent 1.8/32.548
Xref: archiver1.google.com comp.lang.ada:26373
Date: 2002-06-19T14:45:34+02:00
List-Id: <comp.lang.ada>

On Wed, 19 Jun 2002 00:36:20 +0200, Vinzent Hoefler
<JeLlyFish.software@gmx.net> wrote:

>Robert A Duff <bobduff@shell01.TheWorld.com> wrote:
>
>>> 18k11tm001@sneakemail.com (Russ) wrote:
>>> >Every good C++ programmer knows that "+=" is much more efficient than
>>> >"+" for vector/matrix addition because it eliminates the need for
>>> >constructing a temporary matrix to hold the sum.
>
>[...]
>
>>I think Russ is right here.
>>
>>X := F(X, Y);
>>
>>is *not* equivalent to the code that overwrites X in place,
>>in the general case.  In the usual case, where the called function
>>is not inlined, and the compiler doesn't look at its body,
>>the compiler has no hope of doing this optimization.
>>Even if it's inlined, the proof is not trivial.
>
>Hmm, well. Seems I did not take a closer look on what operator
>overloading can do. I still thought of simple C. :(
>
>Anyway, I could declare F (X : inout ...; Y); then, to do the
>assignment for me. ;-)

Yes, but it would be nice to have an operator equivalent for that:

procedure "+:=" (Accum : inout A; Argument : A);

I think it would be relatively easy to add some extra keywords like
"+:=", "-:=" etc. They should have no priorities and one need not
predefine them for any type. 

---
Regards,
Dmitry Kazakov
www.dmitry-kazakov.de