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Botet Escriba" Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: [tuple] extracting tuples out of a tuple Date: Wed, 17 Feb 2016 07:36:49 +0100 Lines: 214 Approved: news@gmane.org Message-ID: <56C41501.4070906@wanadoo.fr> References: <7e08b6c5-853c-471e-b248-a9df7e8e27be@isocpp.org> <67c3c86d-3089-4f07-878a-3f3e706744df@isocpp.org> <42a29c5b-07e4-4e36-bab4-03a7e86ff905@isocpp.org> <6e02dbfe-01f3-4840-92ab-bcc8f7824348@isocpp.org> <47d71f75-7fb7-4589-863c-f5329bc41952@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="------------070400040709060101000005" X-Trace: ger.gmane.org 1455691022 8417 80.91.229.3 (17 Feb 2016 06:37:02 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 17 Feb 2016 06:37:02 +0000 (UTC) Cc: mwoehlke.floss@gmail.com To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDH67CONY4PBBA5KSC3AKGQEND3JN7A@isocpp.org Wed Feb 17 07:36:54 2016 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-lf0-f71.google.com ([209.85.215.71]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1aVvjI-0002mP-Lt for gclcip-std-proposals@m.gmane.org; Wed, 17 Feb 2016 07:36:52 +0100 Original-Received: by mail-lf0-f71.google.com with SMTP id h66sf2203810lfb.0 for ; Tue, 16 Feb 2016 22:36:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-type:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=qqg7AiFZoUvCyFkWaxAs10DkDsQdFlqzeuhzf9iggUs=; b=KkJnIfIu9b0JPdZtlPO5wHTNxg7OHOGaC89zVU/CJUuNeoX1tYbPSNxnxh0AvrKur0 YpyCL2acCJpJ1pJ1lxHnGyhcN24k0qJ0zf9vmzO6O5zfs72+Yg13eXfSdsYTp9f6Mj+X J2umr3VkOEPfsAjv5TVvjBEg/0rouaqo7a2w97bvBHwG+0ELqivQOeoZdpOCoHURQQEh Y+47NwqCZN8r9/t0ky50WCyDNd/kVAdTqbDSF+0K9vcAije38nRhzQP18WSi/87WUTW9 FHZboQ+IuaEvkzoGh+rmIk1tFcrUjk5dULBc4P5dHQ4eEun00/bMiz923/i/ENxB46h6 1ICw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-type:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=qqg7AiFZoUvCyFkWaxAs10DkDsQdFlqzeuhzf9iggUs=; b=hmHkNNwhtho4mEdKgQcV07uvFnhJPnK8WLKlCdO/tsRLY+mUd6DB88eGQvjvNL1P/W heKJZo8rX7/MQ4TlsCED1iZYs4wEcgVlhhCLZj7ECm9CxMb2yb17xYIx/ghSw/R+INtN 5pMumimB+QoPXkKU9C3oNyJzrBH9lUynOG7TD5xgN3e8oXn71FJMFx/50V9xzKXb6TW5 1Dhki+vT8Uq3B+IwihLi+/O35GU6Iipu0pmTG5bGE3ehDpSoPDui2C0RkWqOyJxzfHud rYT2HHh+TUphAOPY9KTac1TNlqKS0Uou+nJmqJju2XQilcqwMLzhzsxsMVtYM9dcRYqO kV X-Gm-Message-State: AG10YOTWxS0a+6vqvCEFjGz+qw00U8aQcHUyM4KhMMyWWu7CefpYHh+6fvuqRnMtUMkKNw== X-Received: by 10.194.19.195 with SMTP id h3mr3057890wje.1.1455691012255; Tue, 16 Feb 2016 22:36:52 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.28.156.130 with SMTP id f124ls954298wme.13.gmail; Tue, 16 Feb 2016 22:36:50 -0800 (PST) X-Received: by 10.194.89.70 with SMTP id bm6mr28490426wjb.0.1455691010604; Tue, 16 Feb 2016 22:36:50 -0800 (PST) Original-Received: from smtp.smtpout.orange.fr (smtp06.smtpout.orange.fr. [80.12.242.128]) by mx.google.com with ESMTPS id wt9si54013227wjc.42.2016.02.16.22.36.50 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 16 Feb 2016 22:36:50 -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 ([81.53.183.74]) by mwinf5d29 with ME id KJcp1s00L1cjLC103Jcqlx; Wed, 17 Feb 2016 07:36:50 +0100 X-ME-Helo: new-host.home X-ME-Auth: dmljZW50ZS5ib3RldEB3YW5hZG9vLmZy X-ME-Date: Wed, 17 Feb 2016 07:36:50 +0100 X-ME-IP: 81.53.183.74 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 In-Reply-To: <47d71f75-7fb7-4589-863c-f5329bc41952@isocpp.org> 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:24436 Archived-At: This is a multi-part message in MIME format. --------------070400040709060101000005 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Le 17/02/2016 00:13, Louis Dionne a =C3=A9crit : > > > On Tuesday, 16 February 2016 16:11:36 UTC-5, Matthew Woehlke wrote: > > (FYI, whatever you used to post your last message just butchered the > quoting. And the line wrapping on your own text isn't much better.) > > > I posted my reply from the Google Groups web page, and both the quoting > and the line wrapping look fine there. I'm not sure what you're=20 > referring to. > > > On 2016-02-16 15:21, Louis Dionne wrote: > > On Monday, 15 February 2016 21:10:52 UTC-5, Nicol Bolas wrote: > >> Oh, and show me the Hana code for this: > >> > >> struct Data > >> { > >> int i; > >> float f; > >> double d; > >> }; > >> > >> Data d =3D ...; > >> outer(inner([:]d)...); > > > > Ah! That's a good one! Here's how you would write it: > > > > BOOST_HANA_DEFINE_STRUCT(Data, > > Oops. That right there is a no-go. Redefining the type is right > out, as > most likely the type is not something that can be directly > controlled. > (Even if it was, uglifying the API like this? No, thanks...) > > > You don't need to redefine the type, since the above macro actually > defines the type itself. If you don't have control over the type, you can > also use BOOST_HANA_ADAPT_STRUCT to adapt an existing struct. > But all of this is completely irrelevant, since I myself said that=20 > these macros > were nothing but workarounds for the lack of proper introspection=20 > facilities, > which need to be built into the language. This is obviously neither where > we disagree nor the subject of this discussion. > > Hi, I agree here with Louis, this is orthogonal. There is a proposal for=20 defaulting tuple-like access [1] that should help here. Vicente [1]=20 https://github.com/viboes/std-make/blob/master/doc/proposal/reflection/P019= 7R0.md --=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/. --------------070400040709060101000005 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Le 17/02/2016 00:13, Louis Dionne a =C3=A9crit=C2=A0:


On Tuesday, 16 February 2016 16:11:36 UTC-5, Matthew Woehlke wrote:
(FYI, whatever you used to post your last message just butchered the
quoting. And the line wrapping on your own text isn't much better.)

I posted my reply from the Google Groups web page, and both the quoting
and the line wrapping look fine there. I'm not sure what you're referring to.
=C2=A0

On 2016-02-16 15:21, Louis Dionne wrote:
> On Monday, 15 February 2016 21:10:52 UTC-5, Nicol Bolas wrote:
>> Oh, and show me the Hana code for this:
>>
>> struct Data
>> {
>> =C2=A0 int i;
>> =C2=A0 float f;
>> =C2=A0 double d;
>> };
>>
>> Data d =3D ...;
>> outer(inner([:]d)...);
>
> Ah! That's a good one! Here's how you would write it:
>
> =C2=A0 =C2=A0 BOOST_HANA_DEFINE_STRUCT(Data,

Oops. That right there is a no-go. Redefining the type is right out, as
most likely the type is not something that can be directly controlled.
(Even if it was, uglifying the API like this? No, thanks...)

You don't need to redefine the type, since the above macro actually
defines the type itself. If you don't have control over the type, you can
also use BOOST_HANA_ADAPT_STRUCT to adapt an existing struct.
But all of this is completely irrelevant, since I myself said that these macros
were nothing but workarounds for the lack of proper introspection facilities,
which need to be built into the language. This is obviously neither where
we disagree nor the subject of this discussion.
=C2=A0

Hi,

I agree here with Louis, this is orthogonal. There is a proposal for defaulting tuple-like access [1] that should help here.

Vicente

[1] https://github.com/viboes/std-make/blob/master/doc/proposal/reflection/P019= 7R0.md

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