From -8589755864230265166 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,305abf126cd51bfd X-Google-Attributes: gidf78e5,public From: steagall@deltalogic.com (Bob Steagall) Subject: Re: implementing persistence with std library Date: 1997/07/29 Message-ID: <33de02bf.4910020@news.apk.net>#1/1 X-Deja-AN: 260219642 References: X-Original-Date: Tue, 29 Jul 1997 15:12:12 GMT Organization: DeltaLogic, Inc. X-Auth: PGPMoose V1.1 PGP comp.std.c++ iQBVAwUBM94Y9Uy4NqrwXLNJAQHsPwH9GAag3H4VZTpLVFqy01gB+BhVyUws0406 iQ7XQGbYSKDh0WJ/Nvts+0f/Rb8UlZwmbAGNIvrjm+vygMNE20m2Sw== =dzop Reply-To: steagall@deltalogic.com Newsgroups: comp.std.c++ Originator: austern@isolde.mti.sgi.com Matt Austern wrote: >No, it doesn't precisely conform to the draft standard. > >One problem is that allocators as defined in the draft standard are >unimplementable without member templates (take a look at the "rebind" >member), and compilers that support member templates are still >uncommon. The SGI implementation uses a design that doesn't require >member templates. > >The situation with member-specific data in the draft standard is a bit >more complicated. What it boils down to is that allocators in the >draft are allowed to have non-static member functions, but standard >containers are allowed to assume that they have no member-specific >data. Containers, as defined in the draft, are allowed to act as if >all allocators of the same type are interchangeable. Hmm, unless I am misreading CD2, I think the last statement should be a little stronger. Containers, as defined in the draft, are (implicitly) *required* to act as if all allocators of the same type are interchangeable. This precludes precisely conforming standard library containers from having/using per-instance private pools of memory. While private pools are something you won't want to use all the time, when you do need them, they can be tremendously faster than shared pools. The XTL implementation extends the allocators and containers to permit private pools, and do the right thing when they are used. --Bob ==================================================================== Bob Steagall steagall@deltalogic.com DeltaLogic, Inc. http://www.deltalogic.com 1537 Kew Road Voice (216) 321-8200 Cleveland Hts, OH 44118-1204 Fax (216) 321-6976 --- [ comp.std.c++ is moderated. To submit articles: Try just posting with your newsreader. If that fails, use mailto:std-c++@ncar.ucar.edu comp.std.c++ FAQ: http://reality.sgi.com/austern/std-c++/faq.html Moderation policy: http://reality.sgi.com/austern/std-c++/policy.html Comments? mailto:std-c++-request@ncar.ucar.edu ]