220 18462 <4A2E09D9-269D-4532-BC8E-DF1FD5B82BA8@gmail.com> article Path: news.gmane.org!not-for-mail From: Howard Hinnant Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Exposing string small string optimization size to avoid heap allocation. Date: Sat, 6 Jun 2015 11:40:38 -0400 Lines: 59 Approved: news@gmane.org Message-ID: <4A2E09D9-269D-4532-BC8E-DF1FD5B82BA8@gmail.com> References: <19736033-58d4-441d-ae73-19804f8ef575@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2098\)) Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1433605260 29648 80.91.229.3 (6 Jun 2015 15:41:00 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 6 Jun 2015 15:41:00 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCK2HM4L6YERB6FIZSVQKGQED2CMEII@isocpp.org Sat Jun 06 17:40:46 2015 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-pd0-f198.google.com ([209.85.192.198]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Z1GDD-0000gq-Al for gclcip-std-proposals@m.gmane.org; Sat, 06 Jun 2015 17:40:43 +0200 Original-Received: by pdmx3 with SMTP id x3sf104828330pdm.1 for ; Sat, 06 Jun 2015 08:40:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:content-type:mime-version:subject:from :in-reply-to:date:content-transfer-encoding:message-id:references:to :x-original-sender:x-original-authentication-results:reply-to :precedence:mailing-list:list-id:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=o8g3UoQNQGMXnTT+P0i9PjxBVILTKZzZccm4Fc9vebA=; b=d5U+Xvp++eCo3b6HkWopdpjIldJhlf+2o2uNbUwZT3SjhN3wNenYAa2vvkgPC8khqd btotPcmqxnqDHzlNCWXOJZPkAU0vNspotSWQKfTXq2LWQmi0APbns6Tu3NggGnYFNxzj rT3JbsWspIf2GD+YxyBmTVlI14FNKFMci/PnRB/Q/NwBiW5kwHfRcfozJDkq0CaWQFUm emCrC93iVMWOTg2PEy/2ZJ/EzsUwy/7jyCKs5PaF1C7A84w8eJn+8ta7qdDFWf9xYa4H TKg8n7D7lcZ4IJyvCRZ+gQdKEORJ+bwL5jeUzpemXsavJj9NZk8y0WbKy50JpekaJOjq Es1w== X-Gm-Message-State: ALoCoQmR7xhHtXAoIoOXD9U3h3kGVpZ7yoSet8AHdoym4RZ7Ar1KbsAuEvhMi6qJcUvYPOEyj+QF X-Received: by 10.66.149.35 with SMTP id tx3mr11018907pab.24.1433605241573; Sat, 06 Jun 2015 08:40:41 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.140.97.136 with SMTP id m8ls2041344qge.94.gmail; Sat, 06 Jun 2015 08:40:40 -0700 (PDT) X-Received: by 10.52.135.50 with SMTP id pp18mr15632868vdb.73.1433605240633; Sat, 06 Jun 2015 08:40:40 -0700 (PDT) Original-Received: from mail-vn0-x243.google.com (mail-vn0-x243.google.com. 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[104.229.168.124]) by mx.google.com with ESMTPSA id s2sm12036758vdh.8.2015.06.06.08.40.39 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sat, 06 Jun 2015 08:40:39 -0700 (PDT) In-Reply-To: <19736033-58d4-441d-ae73-19804f8ef575@isocpp.org> X-Mailer: Apple Mail (2.2098) X-Original-Sender: howard.hinnant@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of howard.hinnant@gmail.com designates 2607:f8b0:400c:c0f::243 as permitted sender) smtp.mail=howard.hinnant@gmail.com; dkim=pass header.i=@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:18462 Archived-At: > On Jun 6, 2015, at 1:14 AM, german.diago@hubblehome.com wrote: >=20 > Hello everyone, >=20 > I would like to know if there would be interest in a proposal for detecti= ng when a string allocates in the heap. >=20 > The rationale for this is that there are environments in which heap alloc= ations should be forbidden, > but use of short strings can still be made, with the convenience of strin= g functions.=20 > Embedded environments are such an example: >=20 >=20 > A static member function (or free?) could be provided. Something like: >=20 > //Pseudo-C++, no basic_string here to go straight to the question > class string { > public: > static std::size_t max_stack_allocated_size(); > static bool needs_dynamic_allocation(std::size_t sz); > }; >=20 > Any interest in this? If you can live without constexpr, you=E2=80=99ve already got it: #include #include template std::size_t max_stack_allocated() { String s; return s.capacity(); } int main() { std::cout << max_stack_allocated() << '\n'; std::cout << max_stack_allocated() << '\n'; } Howard --=20 ---=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. Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposa= ls/. .