220 33508 article Path: news.gmane.org!.POSTED!not-for-mail From: Ville Voutilainen Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Free function std::contains in algoritm and map Date: Tue, 1 Aug 2017 20:31:36 +0300 Lines: 57 Approved: news@gmane.org Message-ID: References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" X-Trace: blaine.gmane.org 1501608704 5085 195.159.176.226 (1 Aug 2017 17:31:44 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 1 Aug 2017 17:31:44 +0000 (UTC) To: "ISO C++ Standard - Future Proposals" Original-X-From: std-proposals+bncBC5JHI7A7ALRB6PVQLGAKGQE3565A6Y@isocpp.org Tue Aug 01 19:31:40 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-pf0-f199.google.com ([209.85.192.199]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dcb13-0000lE-88 for gclcip-std-proposals@m.gmane.org; Tue, 01 Aug 2017 19:31:33 +0200 Original-Received: by mail-pf0-f199.google.com with SMTP id r187sf22563460pfr.8 for ; Tue, 01 Aug 2017 10:31:39 -0700 (PDT) ARC-Seal: i=2; a=rsa-sha256; t=1501608698; cv=pass; d=google.com; s=arc-20160816; b=GcPQ2pkkcXUnt+exWSpyXR5i3zvn+ssrXIgdkZVoLGe16KZCPqaMQ3oiUsqtNoCTsI q14WfJkHo7DH9yBg3vqf2WWwctiXDIKcHL/GBcX9XCalwxsfj0UrLWAijMcRe60rkPBR 4KwafkQTlrxsKKygPDpAGR1pTNgXIkTM0y4326Nf3K862j/NrW/YuGzNI2gPktkuO9pX XJJLFTief4/kKTuGEyHvDvyddvgJPnTfLOjTpLiUw5fUrhkZBNyMO3jmnJGdnaDvkZZ8 yZec1xC02qiM7qWUaMjjyh5aRmMK7/JZGzEwV6kyk5UVQoQgSLtbKPNkRpLq43zeSQgR NEig== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:reply-to:to:subject:message-id:date :from:references:in-reply-to:mime-version:arc-authentication-results :arc-message-signature:dkim-signature:arc-authentication-results; bh=XBlzT2/tb6WByUI/of3wJZp8v2fOY9CUd2vJvQ1j8lw=; b=wk4U0NCJ5jsJ9KN50bxFc2/7IQ9odDELnYjW90U0xcUyYhQTupxQ/KuwvVhylLVtE/ w9OIkECjBgEjECV5mjCu4mIg3LOoonnozt4Ma0ByX9nKbIebFms8WBJkcIsCHkWpDJtl I14qGOi9voXuyuZtDkJ9h2oJh7pNvqvciTMTrR840EoWECybZbBwlk288hnO7m2kx7gb v6hLorCenVcOqhg2ZJQHLamKs4iBinaMBmtVqqRSTvOSXJ6J0s7AuIp2p9GAVFVg3LyS AD1hrIbbEV6ieqH9fvbTaWWV5fssBmDLBf/XySRmVON84wCfF4a0BLDfGAeS2m0U19uY q07w== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@gmail.com header.b=l/W/InHa; spf=pass (google.com: domain of ville.voutilainen@gmail.com designates 2607:f8b0:400c:c05::241 as permitted sender) smtp.mailfrom=ville.voutilainen@gmail.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject: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=XBlzT2/tb6WByUI/of3wJZp8v2fOY9CUd2vJvQ1j8lw=; b=NP9EYLeMT0h8uov5OPhTdTOHwfPlnTwRZqxYKWJ1a9Pdk0sOwqf9pMrEtioqlbBwgf 2x6Em9GGUI5QDn3Q6LYW7q+FDre/burfu0nepqXSev2+FeyKrKb/mff1maJyfpQ3fSei P330LkAyyTwB0WRUJJ5HllKU14iw3FvMy6b5XZMah08AjGFgVfcnSMtPjK5SpDpVQuqj wX1THBCqrD+NZ/06W6/HSZGwzp0PzHH2H5wzNNHIQJGVh0/4Hx0P28YkuBWof/oPRZVd m0i2ptfvzytAEc63RtFlxOcMdlPWWETUVhCjsMmqF9HBR7qPlVKlIZ/EancRCS5HJDMb cDAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=XBlzT2/tb6WByUI/of3wJZp8v2fOY9CUd2vJvQ1j8lw=; b=kQh1Ev+5wMYUjICWeeldwi0D26Qn2LCujMVSCDBhjOpTzipTa+sCd1vRLhuCalSaBB nTJfWQVjjAs3cBjK64GNmNTY7DJkypXOqu+9JTPqNLaoX0fTYTlpDOVBSXv/wGdcmge/ 4z4quxNagP/HPPWolle2TbyRyp78iM2GnUIV0vf2mxL+0hFxN5HFk+UpmdoDUrDTVsOj vVUw/76VotUtvpJa1v7CrcfLWqyr/BX2UdXwNsRDegmsq/bLzvu2pfvfcy3MqOZ1BN+0 3T0eoKnh+7g7Rv1J/v82DXkWxDSCCsoloLHvLD2ypBgEzc5QPFqtV/cat9EUj++OKUub 710A== X-Gm-Message-State: AIVw110d7r/UdO9UrcdzxF03in6oRBuDbrq8wXprqRG9Y+9luVLG6cGp VktIrs0oKVN2mPZF X-Received: by 10.99.147.75 with SMTP id w11mr14663260pgm.77.1501608698306; Tue, 01 Aug 2017 10:31:38 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.36.36.23 with SMTP id f23ls1561233ita.2.gmail; Tue, 01 Aug 2017 10:31:37 -0700 (PDT) X-Received: by 10.159.36.81 with SMTP id 75mr14343365uaq.62.1501608697374; Tue, 01 Aug 2017 10:31:37 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1501608697; cv=none; d=google.com; s=arc-20160816; b=f/ojteHgc/3mEemFwkmxN7QGfilE1AaxVGxGlxke77l2eu1VhHtXOvXrdg9K0d8nou k1ryduMv7WR/aRSMAkdA2ReiiXJXSQ7rDDn2dVqAlSIlzvtT6QKW8GpE9snY7ujrGGcv KkjBQ8sUoaW9IzQp/2Rkq+h086J5jOXwKnZA3nsSSxG8WOZyH2SrSNauz0B+PJ5w1vP/ cMx2CA5AxNgFJ0ncWkM0XxPNqPR02PrRHWdmx9WATJ+1+VxzzHqo0Fu0xvZ3eutC7pJN p5fG0DfD6cdtQNraIcK90YrF94x7/GzqtCrcKl/P0YoYLe2hCgne+pMOE+yekwp10Mb1 lGjg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=to:subject:message-id:date:from:references:in-reply-to:mime-version :dkim-signature:arc-authentication-results; bh=/4ESexXUdmY5XLT8xE3JpnAQUvSudfq40Ein1gfb2yA=; b=bzFYpHCXZC7Ew8gSp/rUb1Rg30YC2WTgMba6iaw3ejvp6B0y2CbFFvuDwcUzutlqzq efE8XuU5+Gy4kkpsVMkG6EhVacsZ4fsiDDeBFYH8Cj7HF8o4FiscLnzmyerBZrk6pB/N PUE/pLZQ4u3Hi1K9yzGoSr3Y0sDJJjQFAOb9mx88+379cZyEEYpDXIjKnJrR0yo7+I1k mpeNFbPPk/liOOWOAZ1SAReCG3xrsWTWJk2STa0KqGfOGrlWjUsNrnxzIBO9k8M4s7Sb qGVfD07pUvQ2vELnXHbxmvnZghTYz5xRTplbDm/ciVm3jdTAClO6/1VleDU/ufaiVpiq OfqA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.b=l/W/InHa; spf=pass (google.com: domain of ville.voutilainen@gmail.com designates 2607:f8b0:400c:c05::241 as permitted sender) smtp.mailfrom=ville.voutilainen@gmail.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gmail.com Original-Received: from mail-vk0-x241.google.com (mail-vk0-x241.google.com. [2607:f8b0:400c:c05::241]) by mx.google.com with ESMTPS id h8si2194270uac.309.2017.08.01.10.31.37 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 01 Aug 2017 10:31:37 -0700 (PDT) Received-SPF: pass (google.com: domain of ville.voutilainen@gmail.com designates 2607:f8b0:400c:c05::241 as permitted sender) client-ip=2607:f8b0:400c:c05::241; Original-Received: by mail-vk0-x241.google.com with SMTP id g189so1093547vke.0 for ; Tue, 01 Aug 2017 10:31:37 -0700 (PDT) X-Received: by 10.31.12.136 with SMTP id 130mr4672023vkm.164.1501608696980; Tue, 01 Aug 2017 10:31:36 -0700 (PDT) Original-Received: by 10.103.103.65 with HTTP; Tue, 1 Aug 2017 10:31:36 -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.b=l/W/InHa; spf=pass (google.com: domain of ville.voutilainen@gmail.com designates 2607:f8b0:400c:c05::241 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:33508 Archived-At: On 1 August 2017 at 20:29, Ville Voutilainen wrote: > On 1 August 2017 at 20:26, Ville Voutilainen > wrote: >> On 1 August 2017 at 20:22, wrote: >>> Instead of comparing with end(), there could be a new function - contains. >>> >>> Now >>> >>> if(std::find(vector.begin(), vector.end(), item) != vector.end()){ >>> // found >>> } else { >>> // not found >>> } >>> >>> // maps >>> >>> if(map.find("key") != map.end()){ >>> // found >>> } else { >>> // not found >>> } >>> >>> >>> >>> I propose "contains" function: >>> >>> if(std::contains(vector.begin(), vector.end(), item)){ >>> // found >>> } else { >>> // not found >>> } >>> >>> // maps >>> >>> if(map.contains("key")){ >>> // found >>> } else { >>> // not found >>> } >> >> >> Just use std::count and map::count. > > ..well, except that wastes cycles since it won't stop before the end > of the range for vector. ...which means that for vector, any_of is what you want. It's not named 'contains', and you'll just have to live with it. -- 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/CAFk2RUZ8BFq-EEtoEa4hfBkyiTHBSEyYnHS8XrHAC_Rg0t%2Byhg%40mail.gmail.com. .