220 34255 article Path: news.gmane.org!.POSTED!not-for-mail From: Ville Voutilainen Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Proposal to add constructors to std::bad_alloc exception class. 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[209.85.220.41]) by mx.google.com with SMTPS id a27sor619367uaf.65.2017.09.01.12.35.04 for (Google Transport Security); Fri, 01 Sep 2017 12:35:04 -0700 (PDT) Received-SPF: pass (google.com: domain of ville.voutilainen@gmail.com designates 209.85.220.41 as permitted sender) client-ip=209.85.220.41; X-Received: by 10.159.40.102 with SMTP id c93mr1815040uac.51.1504294502678; Fri, 01 Sep 2017 12:35:02 -0700 (PDT) Original-Received: by 10.103.103.135 with HTTP; Fri, 1 Sep 2017 12:35:02 -0700 (PDT) In-Reply-To: X-Original-Sender: ville.voutilainen@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=oX/mjjS0; spf=pass (google.com: domain of ville.voutilainen@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=ville.voutilainen@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:34255 Archived-At: On 1 September 2017 at 22:28, Rich Sposato wrote: > Hi, > > I wrote this proposal after discovering the std::bad_alloc exception class > only has a default constructor. Other exception classes have constructors > with a string parameter. The lack of a similar constructor in bad_alloc has > caused problems for me. > > This is the second draft of this proposal. Please provide feedback on how to > improve it before I submit it. > > I would especially prefer feedback on wording and style so that it conforms > with the wording and style of accepted proposals. I would also like feedback > on technical correctness. I have a technical question. The proposed signatures look like bad_alloc needs to store a copy of the data passed as an argument for the constructor. How likely is storing that copy to fail right after an allocation failure? I have a follow-up question: did you consider the alternative where the caller of the new constructor must pass an rvalue reference to a std::string, in which case there would be most likely a much smaller allocation, as in the case of a dynamically allocated string that doesn't fit into SSO, there would be none, and in the SSO case, a very small allocation that is not dynamic? Another question I have is this: what sort of ABI impact will this change have for existing standard library implementations? -- 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/CAFk2RUaAOnPnLsUc5SpycK9dTpeT60%2BVt0dQFbSPMROb7JCf0w%40mail.gmail.com. .