220 28942 article Path: news.gmane.org!.POSTED!not-for-mail From: Tony V E Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Is World's Dumbest Pointer still on the table?!? 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[2a00:1450:400c:c09::229]) by mx.google.com with ESMTPS id 10si49743972wjf.6.2016.10.18.09.29.24 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Oct 2016 09:29:24 -0700 (PDT) Received-SPF: pass (google.com: domain of tvaneerd@gmail.com designates 2a00:1450:400c:c09::229 as permitted sender) client-ip=2a00:1450:400c:c09::229; Original-Received: by mail-wm0-x229.google.com with SMTP id d128so452990wmf.1 for ; Tue, 18 Oct 2016 09:29:24 -0700 (PDT) X-Received: by 10.28.65.215 with SMTP id o206mr1318888wma.41.1476808164194; Tue, 18 Oct 2016 09:29:24 -0700 (PDT) Original-Received: by 10.28.157.23 with HTTP; Tue, 18 Oct 2016 09:29:23 -0700 (PDT) In-Reply-To: X-Original-Sender: tvaneerd@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com; spf=pass (google.com: domain of tvaneerd@gmail.com designates 2a00:1450:400c:c09::229 as permitted sender) smtp.mailfrom=tvaneerd@gmail.com; dmarc=pass (p=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:28942 Archived-At: --001a1148e288073d69053f263282 Content-Type: text/plain; charset=UTF-8 On Tue, Oct 18, 2016 at 8:16 AM, Bo Persson wrote: > > > Having similar functions use the same names as functions of the slighlty > smarter pointers, might help replacing those with an observer_pointer. > Changing "release" into "stop_observing" (or something) doesn't appeal to > me. > > > If we look at a similar problem in merging "optional", "variant", and > "any" into the draft standard, we ended up with two of them having a "bool > has_value()" function, while the third got a "bool > valueless_by_exception()". > > Not only do they have different names, but also different true/false > return value for the same(?) condition - does it store anything. > This was very intentional. optional and any are expected to be empty, variant is not. My personal suggestion is to never call valueless_by_exception(). Depends on your codebase and type of product, but in most cases, if your variant got into the valueless state, you have bigger problems to worry about. > Bo Persson > > -- Be seeing you, Tony -- 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/CAOHCbivK2Hu5ch58FC9dPb5RfnKVDrd5Sj4b7hJMUKkTciZtng%40mail.gmail.com. --001a1148e288073d69053f263282 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable


On Tue, Oct 18, 2016 at 8:16 AM, Bo Persson <bop@gmb.dk> wrote:=


Having similar functions use the same names as functions of the slighlty sm= arter pointers, might help replacing those with an observer_pointer. Changi= ng "release" into "stop_observing" (or something) doesn= 't appeal to me.


If we look at a similar problem in merging "optional", "vari= ant", and "any" into the draft standard, we ended up with tw= o of them having a "bool has_value()" function, while the third g= ot a "bool valueless_by_exception()".

Not only do they have different names, but also different true/false return= value for the same(?) condition - does it store anything.
=


This was very intentional.=C2=A0 optional and any a= re expected to be empty, variant is not.=C2=A0 My personal suggestion is to= never call valueless_by_exception().=C2=A0 Depends on your codebase and ty= pe of product, but in most cases, if your variant got into the valueless st= ate, you have bigger problems to worry about.



=C2=A0 =C2=A0Bo Persson



--
Be = seeing you,
Tony

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