220 34976 <551eb493-f49d-412d-98d2-9a5d96f68104@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: Aleksey Loginov Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Idea about "std::pmr::memory_resource" Date: Mon, 16 Oct 2017 23:22:07 -0700 (PDT) Lines: 99 Approved: news@gmane.org Message-ID: <551eb493-f49d-412d-98d2-9a5d96f68104@isocpp.org> References: <0a8293b4-3246-47a5-9881-bc1ca4b91772@isocpp.org> <07ddb1f6-d3af-43df-bf96-8975c1ab4313@isocpp.org> <2e191a96-1952-479b-b78b-22e31f8e03de@isocpp.org> <0e37b5ae-64f6-4a8a-86bd-f44b119ed40a@isocpp.org> <15f8c5ba-3a6a-4441-9620-92e157c66094@isocpp.org> <26fe4cb4-98ca-41cc-ac96-5c51851799d1@isocpp.org> <784ffce8-ace7-449d-a13d-a99d7336117a@isocpp.org> <6d0ad98b-87d5-43dd-ac54-2b7d3e03e31b@isocpp.org> <4af80cf7-244c-4137-9133-1a36a209e4ca@isocpp.org> <7f22751b-91d1-4de4-81d2-421046ceb963@isocpp.org> <68690e5c-f466-4fbe-ab41-80be58257259@isocpp.org> <664105b3-ea68-4565-8017-a4893f4b38bf@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; 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Mon, 16 Oct 2017 23:22:08 -0700 (PDT) X-Received: by 10.31.201.198 with SMTP id z189mr37579vkf.0.1508221328388; Mon, 16 Oct 2017 23:22:08 -0700 (PDT) In-Reply-To: <664105b3-ea68-4565-8017-a4893f4b38bf@isocpp.org> X-Original-Sender: Aleksey.Loginov@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:34976 Archived-At: ------=_Part_18673_2031292878.1508221327709 Content-Type: multipart/alternative; boundary="----=_Part_18674_46590738.1508221327709" ------=_Part_18674_46590738.1508221327709 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =D0=B2=D1=82=D0=BE=D1=80=D0=BD=D0=B8=D0=BA, 17 =D0=BE=D0=BA=D1=82=D1=8F=D0= =B1=D1=80=D1=8F 2017 =D0=B3., 4:29:15 UTC+3 =D0=BF=D0=BE=D0=BB=D1=8C=D0=B7= =D0=BE=D0=B2=D0=B0=D1=82=D0=B5=D0=BB=D1=8C Mingxin Wang=20 =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB: > > On Tuesday, October 17, 2017 at 1:39:33 AM UTC+8, Aleksey Loginov wrote: >> >> In other words, by hand-made RTTI, and only for fixed allocation=20 >> starategies (for example, data_ can not be a shared_ptr or cow_ptr= ) >> > > There is NO RTTI in the implementation of "operator=3D". This operation i= s=20 > done via indirect function calls, and it is as efficient as most=20 > implementations of `std::any` from various vendors. > > `data_` is actually implementation detail, I don't know about your=20 > motivation that it should be shared_ptr or cow_ptr. > > Mingxin Wang > You are just simulate RTTI via function pointers and meta-type pointer (con= st=20 manager_t*). Motivation is simple: do not copy big data, when it's not needed. Passing= =20 policy in constructor like in_place_type_t can do the job. --=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/551eb493-f49d-412d-98d2-9a5d96f68104%40isocpp.or= g. ------=_Part_18674_46590738.1508221327709 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

=D0=B2=D1=82=D0=BE=D1=80=D0=BD=D0=B8=D0=BA, 17 =D0=BE= =D0=BA=D1=82=D1=8F=D0=B1=D1=80=D1=8F 2017 =D0=B3., 4:29:15 UTC+3 =D0=BF=D0= =BE=D0=BB=D1=8C=D0=B7=D0=BE=D0=B2=D0=B0=D1=82=D0=B5=D0=BB=D1=8C Mingxin Wan= g =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB:
On Tuesday, October 17, 2017 at 1:39:33 AM = UTC+8, Aleksey Loginov wrote:
In other words, by hand-made RTTI, and only for fixed alloc= ation starategies (for example, data_ can not be a shared_ptr<T> or c= ow_ptr<T>)

There is NO RT= TI in the implementation of "operator=3D". This operation is done= via indirect function calls, and it is as efficient as most implementation= s of `std::any` from various vendors.

`data_` is a= ctually implementation detail, I don't know about your motivation that = it should be shared_ptr<T> or cow_ptr<T>.

<= div>Mingxin Wang

You are just s= imulate RTTI via function pointers and meta-type pointer (const manager_t*).

Motivation is= simple: do not copy big data, when it's not needed. Passing policy in = constructor like=C2=A0in_place_type_t=C2= =A0can do the job.

--
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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/551eb493-f49d-412d-98d2-9a5d96f68104= %40isocpp.org.
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