220 31455 article Path: news.gmane.org!.POSTED!not-for-mail From: "dgutson ." Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: overloading by constexpr (round 2?) 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[2607:f8b0:400c:c08::22f]) by mx.google.com with ESMTPS id w2si7090776uaf.32.2017.03.06.10.15.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 Mar 2017 10:15:52 -0800 (PST) Received-SPF: pass (google.com: domain of danielgutson@gmail.com designates 2607:f8b0:400c:c08::22f as permitted sender) client-ip=2607:f8b0:400c:c08::22f; Original-Received: by mail-ua0-x22f.google.com with SMTP id u30so46950577uau.0 for ; Mon, 06 Mar 2017 10:15:52 -0800 (PST) X-Received: by 10.176.6.167 with SMTP id g36mr6672603uag.10.1488824152433; Mon, 06 Mar 2017 10:15:52 -0800 (PST) Original-Received: by 10.103.64.13 with HTTP; Mon, 6 Mar 2017 10:15:51 -0800 (PST) X-Original-Sender: danielgutson@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com; spf=pass (google.com: domain of danielgutson@gmail.com designates 2607:f8b0:400c:c08::22f as permitted sender) smtp.mailfrom=danielgutson@gmail.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=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:31455 Archived-At: --94eb2c047d42bd2b8b054a13e246 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable I'm proposing the ability to provide two versions of a function, overloaded by the constexpr specifier: one constexpr version and another non-constexpr version, and let the compiler use the appropriate one according to the context. A slightly similar subject has been discussed before ( https://groups.google.com/a/isocpp.org/d/topic/std-proposals/oxijwTY-ft4/di= scussion ). Additionally, people seems to be interested in detecting constexpr-ness (e.g. http://stackoverflow.com/questions/15232758/detecting-constexpr-with-sfinae= ) to achieve the same "manually". I'm talking about to make this simpler: constexpr int f() { return 1; } int f() { return 2; } constexpr auto a =3D f(); // a =3D 1 auto fun =3D std::function(f); int b =3D fun(); // b =3D 2 If there is some interest, I can star working in a gcc fork as a prototype. BRgds, Daniel. --=20 Who=E2=80=99s got the sweetest disposition? One guess, that=E2=80=99s who? Who=E2=80=99d never, ever start an argument? Who never shows a bit of temperament? Who's never wrong but always right? Who'd never dream of starting a fight? Who get stuck with all the bad luck? --=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. To view this discussion on the web visit https://groups.google.com/a/isocpp= ..org/d/msgid/std-proposals/CAFdMc-2q3KpV%2Bm5cfWr6b02XmHVUdxsNCNAVFG%2BmzCv= 0QY7ZRg%40mail.gmail.com. --94eb2c047d42bd2b8b054a13e246 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I'm proposing the ability to provide two ver= sions of a function,=20 overloaded by the constexpr specifier: one constexpr version and another non-constexpr version, and let the compiler use the appropriate one=20 according to the context.

A slightly similar subjec= t has been discussed before (https://groups.google.com= /a/isocpp.org/d/topic/std-proposals/oxijwTY-ft4/discussion ).
=
Additionally, people seems to be interested in detecting constexpr-nes= s (e.g. http://stackoverflow.com/questions/15232758/detecting-= constexpr-with-sfinae) to achieve the same "manually".
I'm talking about to make this simpler:

c= onstexpr int f()
{
=C2=A0=C2=A0=C2=A0 return 1;
<= div>}

int f()
{
=C2=A0=C2=A0=C2=A0 retur= n 2;
}

constexpr auto a =3D f();=C2=A0=C2= =A0=C2=A0 // a =3D 1
auto fun =3D std::function<int(void)&= gt;(f);
int b =3D fun();=C2=A0=C2=A0 // b =3D 2

=
If there is some interest, I can star working in a gcc fork as a = prototype.

BRgds,

=C2=A0=C2=A0=C2=A0 Da= niel.


--
Who=E2=80= =99s got the sweetest disposition?
One guess, that=E2=80=99s who?
Who= =E2=80=99d never, ever start an argument?
Who never shows a bit of tempe= rament?
Who's never wrong but always right?
Who'd never dream= of starting a fight?
Who get stuck with all the bad luck?

--
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