220 41468 <8a165c32-718a-4247-93b4-44235a2cf122@isocpp.org> article Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: will wray Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Allow array as function return value Date: Mon, 18 Feb 2019 08:24:36 -0800 (PST) Approved: news@gmane.org Message-ID: <8a165c32-718a-4247-93b4-44235a2cf122@isocpp.org> References: Reply-To: std-proposals@isocpp.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_693_1766519651.1550507077021" Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="81372"; mail-complaints-to="usenet@blaine.gmane.org" To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBC7LL4HG4IBRBRNYVPRQKGQEBGR2ZNA@isocpp.org Mon Feb 18 17:24:46 2019 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yw1-f71.google.com ([209.85.161.71]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1gvlin-000Kpo-J1 for gclcip-std-proposals@m.gmane.org; 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Mon, 18 Feb 2019 08:24:38 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 2002:a81:2f0a:: with SMTP id v10ls5163914ywv.10.gmail; Mon, 18 Feb 2019 08:24:37 -0800 (PST) X-Received: by 2002:a81:5f89:: with SMTP id t131mr218778ywb.2.1550507077568; Mon, 18 Feb 2019 08:24:37 -0800 (PST) In-Reply-To: X-Original-Sender: wjwray@gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: 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:41468 Archived-At: ------=_Part_693_1766519651.1550507077021 Content-Type: multipart/alternative; boundary="----=_Part_694_347649933.1550507077022" ------=_Part_694_347649933.1550507077022 Content-Type: text/plain; charset="UTF-8" std::array is long in the tooth as an early C++11 demo class. std::array hasn't proved itself as a 'vocabulary' type for API usage - spans and ranges supersede and they operate fine with built-in array. std::array does not 'roundtrip' the wrapped array type; data() returns a pointer. std::array tuple-access customization for structured binding access trumps the regular aggregate structured binding access which would have given direct 'roundtrip' access... std::array is awkward to use for multidimensional arrays. std::array CTAD guides added for 17 only give 'all or none' deduction - you can't provide just the type and deduce size - function's deducing built-in array are more flexible. std::array doesn't have C-linkage. std::array may add end-padding (?). Built-in array, despite the danger, is a simple language-level solution. Built-in array has std::swap specialization... On Monday, February 18, 2019 at 10:49:31 AM UTC-5, Manuel Bergler wrote: > > > Am Mo., 18. Feb. 2019 um 16:30 Uhr schrieb will wray >: > >> [...] >> >> With array return allowed, struct wrappers like std::array are not >> necessary: >> > > What's wrong with std::array as a function return type? Both returning > with brace-init and structured bindings work for std::array. > > -- 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 email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/8a165c32-718a-4247-93b4-44235a2cf122%40isocpp.org. ------=_Part_694_347649933.1550507077022 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
std::array is long in the tooth as an early C++11 dem= o class.

std::array hasn't proved itself as a = 'vocabulary' type for API usage -
spans and ranges supers= ede and they operate fine with built-in array.

std= ::array does not 'roundtrip' the wrapped array type; data() returns= a pointer.
std::array tuple-access customization for structu= red binding access trumps the regular
aggregate structured bindin= g access which would have given direct 'roundtrip' access...
<= div>std::array is awkward to use for multidimensional arrays.
std::array CTAD guides added for 17 only give 'all or none' d= eduction - you can't provide
just the type and deduc= e size - function's deducing built-in array are more flexible.

std::array doesn't have C-linkage.
std::array may add end-padding (?).

Built-in array, despite the danger, is a simple language-level sol= ution.
Built-in array has std::swap specialization...=C2=A0
=

On Monday, February 18, 2019 at 10:49:31 AM UTC-5, Manuel Bergler = wrote:

Am Mo., 18.= Feb. 2019 um 16:30=C2=A0Uhr schrieb will wray <wjw...@gmail.com>:
=
[...]

With array return allowed, struct wrapper= s like std::array are not necessary:
=C2=A0
What's wrong with std::array as a function return type? Both re= turning with brace-init and structured bindings work for std::array.
<= div>=C2=A0

--
You received this message because you are subscribed to the Google Groups &= quot;ISO C++ Standard - Future Proposals" group.
To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposa= ls+unsubscribe@isocpp.org.
To post to this group, send email to std-proposals@isocpp.org.
To view this discussion on the web visit https://groups.google.= com/a/isocpp.org/d/msgid/std-proposals/8a165c32-718a-4247-93b4-44235a2cf122= %40isocpp.org.
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