220 39873 article Path: news.gmane.org!.POSTED!not-for-mail From: Nicol Bolas Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Named Parameters for C++ Date: Fri, 17 Aug 2018 10:30:46 -0700 (PDT) Lines: 129 Approved: news@gmane.org Message-ID: References: <823c098a-0fb0-18c3-82f3-e8a8616312f1@gmail.com> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_979_980756520.1534527046877" X-Trace: blaine.gmane.org 1534526922 14946 195.159.176.226 (17 Aug 2018 17:28:42 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 17 Aug 2018 17:28:42 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCEKFTV6ZUMBBR4M3TNQKGQEBGGNLLQ@isocpp.org Fri Aug 17 19:28:38 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yw1-f70.google.com ([209.85.161.70]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fqiYA-0003kT-7A for gclcip-std-proposals@m.gmane.org; Fri, 17 Aug 2018 19:28:38 +0200 Original-Received: by mail-yw1-f70.google.com with SMTP id p8-v6sf6420750ywl.14 for ; Fri, 17 Aug 2018 10:30:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=v0iNmaBion8tpQql0j1GugWG6STMseuKg/LorwbX20o=; b=zg01Dw2n9+9z3Szx8aS9NoLupmtDEQkzgwaViPvOCaKaqydvJ+vrjZmST5DKDrwQzp bApaDXbR1M7tqEy49yzY7zUbGZvMqHhlz2zgBGAKwWjW9j+hqlecaiSfRoVFg4MAc+Fb pRUorQ9WwuxqP1yKuAoQRQ8XNTNF12E5+78GFYLQlir+o/GzBBZK1kZ5wxzADG40bRqR gjhAl1BCa8I6hAvaAxHyUIRCP0tFWEmWbaOrty+33gcfsoibQKQDMOd7RMBiXTNN1P/L ocZ2iw+orEttTfK59GUATOaLrH1AiHq+XvylY6WEzHZlzk0HPf1ThU2YDkMHXHot9+WC fMVg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=v0iNmaBion8tpQql0j1GugWG6STMseuKg/LorwbX20o=; b=unmPB+pu/kLhnfF6Wa0Ct3wJ0xeUvT4Nr3QIemLJ1K7+trJDLDqz3Z/dinwiPqHChT JyICT4MmEb6tKquF/lpb2ZCTiTQVx9DgT7gdtU1ycVuI6qSS7rHkoZt9MiggztS/9qpe CPfenD82p0lsIO3ZSgdj6XZJELReoe0NaH+XTlm0bkAysXr6CJjfl59M31mnCLWLZcRx F0+4XV73AlYd4fbQkEF5MSpwGTXg7aVDKRP05wm5UEHpkKDDqEYA+yDXfUVa5Pkc7gnD 5lIY+AhfzO8PpFyV7eqq5qA/tmGe7Z/aCgyilr0ZC2i1vBcR4g7q5DVSe6x/sp44K4ZO 7glw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:message-id:in-reply-to:references :subject:mime-version:x-original-sender:reply-to:precedence :mailing-list:list-id:x-spam-checked-in-group:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=v0iNmaBion8tpQql0j1GugWG6STMseuKg/LorwbX20o=; b=e+jNa8wRN4ukKgui424ofR1PnQiAl8QPA+u11mz/bRDa5uBpFB4ANe9L8+bDv8T1Qp x9Vt8FqxodQnuUF9LoAxPV6f/Se+uj+Iu4fpVBnjwcD+lR/xLCLzSBV/qgyhecGAU4zH 1IWzM7zEkxt+aNsl6gGlAjqSMI8asnj91zixS0WZzfepgBvj6g2zGa5CNJOD0friRy7E 7W8IGQUpJqphZ6M93tzdCIeqyI8hqEU+8hkgdrA1K+vNE6Yua42vCRPArncNDPmRBRdE LdAMlHD8UjW619r5CdvQy8NrF/MP1APkd4tatMaFrtZxpQMqTjntU8aRi2zpBl+B/uZy Eu2g== X-Gm-Message-State: AOUpUlFAkMGYrqVqbJAy/lA0MLdXz+t1e+MvyahTYfajbenmDLHCb+b4 vE7jpy185A3zuL5JRxKxg8TuTw== X-Google-Smtp-Source: AA+uWPxzJqMDHUfyyA70M58RWksZgN6hRCTm65O7OaRGZGEnOVyIrSM632QoIacZ/0mPff5hlWCy2w== X-Received: by 2002:a81:a10c:: with SMTP id y12-v6mr1369540ywg.231.1534527048513; Fri, 17 Aug 2018 10:30:48 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 2002:a25:238d:: with SMTP id j135-v6ls1711703ybj.15.gmail; Fri, 17 Aug 2018 10:30:47 -0700 (PDT) X-Received: by 2002:a25:4ec6:: with SMTP id c189-v6mr438798ybb.6.1534527047357; Fri, 17 Aug 2018 10:30:47 -0700 (PDT) In-Reply-To: X-Original-Sender: jmckesson@gmail.com 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:39873 Archived-At: ------=_Part_979_980756520.1534527046877 Content-Type: multipart/alternative; boundary="----=_Part_980_111926103.1534527046877" ------=_Part_980_111926103.1534527046877 Content-Type: text/plain; charset="UTF-8" On Friday, August 17, 2018 at 1:12:20 PM UTC-4, David Brown wrote: > > On 17/08/18 17:16, Matthew Woehlke wrote: > > On 2018-08-17 06:14, David Brown wrote: > >> On 16/08/18 15:08, mihailn...@gmail.com wrote: > >>> There are tree major problems with such simple approaches > >>> > >>> First - you make something, that has been private for 30+ years, > public. > >> > >> No, it is not. The names for parameters are in function declarations, > >> in headers - these are public. > > > > No, they aren't. Or, more correctly, while they are "public" in the > > sense that a user can see them by reading the header, they aren't a > > (normative) part of the API, any more than comments are. To *the > > compiler*, they may as well not exist. > > > > You are proposing to change that. That is a *serious* change. > > > > Nah, you are overreacting. At most, it is a /tiny/ issue compared to > the huge amount of implementation stuff in typical C++ headers that > really is supposed to be private implementation details. (Hint: lots of > it is labelled "private:".) > "Overreacting"? Show me a standard library implementation that actually uses the parameter names that the standard library defines. What's more, standard libraries *cannot* use those parameter names. Why? Macro defensiveness. Users can define macros with almost any names. And standard library headers are *required* to not be affected by such macros. As such, standard library implementations are required to use the set of names that macros cannot touch: names that are restricted for the implementation. So if you can't even rely on the standard library's parameter names, you would be unable to write cross-platform code that uses those names. And if you can't even rely on the *standard* library... what *can* you rely on? -- 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/c2700ce4-bf0d-4176-b7c0-df038241f4a7%40isocpp.org. ------=_Part_980_111926103.1534527046877 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Friday, August 17, 2018 at 1:12:20 PM UTC-4, Da= vid Brown wrote:
On 17/08/18 17= :16, Matthew Woehlke wrote:
> On 2018-08-17 06:14, David Brown wrote:
>> On 16/08/18 15:08, mihailn...@gmail.com wrote:
>>> There are tree major problems with such simple approaches= =20
>>>
>>> First - you make something, that has been private for 30+ = years, public.
>>
>> No, it is not. =C2=A0The names for parameters are in function = declarations,
>> in headers - these are public.
>=20
> No, they aren't. Or, more correctly, while they are "publ= ic" in the
> sense that a user can see them by reading the header, they aren= 9;t a
> (normative) part of the API, any more than comments are. To *the
> compiler*, they may as well not exist.
>=20
> You are proposing to change that. That is a *serious* change.
>=20

Nah, you are overreacting. =C2=A0At most, it is a /tiny/ issue compared= to
the huge amount of implementation stuff in typical C++ headers that
really is supposed to be private implementation details. =C2=A0(Hint: l= ots of
it is labelled "private:".)

"Overreacting"? Show me a standard library implementation that= actually uses the parameter names that the standard library defines. What&= #39;s more, standard libraries cannot use those parameter names. Why= ?

Macro defensiveness.

Us= ers can define macros with almost any names. And standard library headers a= re required to not be affected by such macros. As such, standard lib= rary implementations are required to use the set of names that macros canno= t touch: names that are restricted for the implementation.

So if you can't even rely on the standard library's parame= ter names, you would be unable to write cross-platform code that uses those= names. And if you can't even rely on the standard library... wh= at can you rely on?

--
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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/c2700ce4-bf0d-4176-b7c0-df038241f4a7= %40isocpp.org.
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