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[80.12.242.128]) by mx.google.com with ESMTPS id lk6si11371114wjb.21.2016.01.14.10.32.18 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 14 Jan 2016 10:32:18 -0800 (PST) Received-SPF: neutral (google.com: 80.12.242.128 is neither permitted nor denied by best guess record for domain of vicente.botet@wanadoo.fr) client-ip=80.12.242.128; Original-Received: from new-host.home ([92.139.160.222]) by mwinf5d64 with ME id 5uYJ1s0024oBxcU03uYJ6y; Thu, 14 Jan 2016 19:32:18 +0100 X-ME-Helo: new-host.home X-ME-Auth: dmljZW50ZS5ib3RldEB3YW5hZG9vLmZy X-ME-Date: Thu, 14 Jan 2016 19:32:18 +0100 X-ME-IP: 92.139.160.222 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 In-Reply-To: X-Original-Sender: vicente.botet@wanadoo.fr X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 80.12.242.128 is neither permitted nor denied by best guess record for domain of vicente.botet@wanadoo.fr) smtp.mailfrom=vicente.botet@wanadoo.fr Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Spam-Checked-In-Group: std-proposals@isocpp.org X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:23719 Archived-At: This is a multi-part message in MIME format. --------------070004050100070703020103 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Le 14/01/2016 08:47, Andrzej Krzemie=C5=84ski a =C3=A9crit : > > > W dniu wtorek, 12 stycznia 2016 23:49:14 UTC+1 u=C5=BCytkownik Vicente J.= =20 > Botet Escriba napisa=C5=82: > > > Default|swap|/|hash_value| > > Defining|swap|and|hash_value|P0029R0 > as > well as comparison operators, as proposed inN4475 > , > for simple classes is tedious, repetitive, slightly error-prone, > and easily automated. > > Any comments are welcome, > > Hi Vicente, > My intuition tells me that it would be beneficial to make it two=20 > separate proposals. I expect that swap and hash have different=20 > constraints, would rise different concerns, different discussions, and=20 > perhaps different outcomes as to whether include them or not. I can=20 > see that Howard only commented on the hash part. I, in contrast, will=20 > only comment on the swap part. > Ok, I will split it. > I would add to the rationale for swap. Additional benefit for a=20 > default member-wise swap (rather than relying on the move-based)=20 > (apart from performance) is that the former can sometimes offer a=20 > better noexcept guarantee. E.g., for std::vector, swap can be always=20 > guaranteed to be noexcept, whereas its move operations throw. > You are right. I will add it. Vicente --=20 ---=20 You received this message because you are subscribed to the Google Groups "= ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. Visit this group at https://groups.google.com/a/isocpp.org/group/std-propos= als/. --------------070004050100070703020103 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Le 14/01/2016 08:47, Andrzej Krzemie=C5=84ski a =C3=A9crit=C2=A0:


W dniu wtorek, 12 stycznia 2016 23:49:14 UTC+1 u=C5=BCytkownik Vicent= e J. Botet Escriba napisa=C5=82:

Default=C2=A0swap/hash_value

Defining=C2=A0swap=C2=A0and=C2=A0hash_value=C2=A0P0029R0=C2=A0as well as comparis= on operators, as proposed in=C2=A0N4475, for simple classes is tedious, repetitive, slightly error-prone, and easily automated.

Any comments are welcome,

Hi Vicente,
My intuition tells me that it would be beneficial to make it two separate proposals. I expect that swap and hash have different constraints, would rise different concerns, different discussions, and perhaps different outcomes as to whether include them or not. I can see that Howard only commented on the hash part. I, in contrast, will only comment on the swap part.

Ok, I will split it.
I would add to the rationale for swap. Additional benefit for a default member-wise swap (rather than relying on the move-based) (apart from performance) is that the former can sometimes offer a better noexcept guarantee. E.g., for std::vector, swap can be always guaranteed to be noexcept, whereas its move operations throw.

You are right. I will add it.

Vicente

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