220 36651 <959f20d3-0455-951d-70fe-60bf0110cad7@gmail.com> article Path: news.gmane.org!.POSTED!not-for-mail From: Oleksandr Pikozh Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Why std::optional has checked and unchecked access, but std::variant only checked? 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[93.73.45.89]) by smtp.gmail.com with ESMTPSA id i15sm228558lfj.4.2018.01.15.22.33.47 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 15 Jan 2018 22:33:49 -0800 (PST) Content-Language: en-US X-Original-Sender: o.pikozh@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=pMRoMBpC; spf=pass (google.com: domain of o.pikozh@gmail.com designates 209.85.220.41 as permitted sender) smtp.mailfrom=o.pikozh@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-Spam-Checked-In-Group: std-proposals@isocpp.org 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:36651 Archived-At: In std::optional we have: - operator* =E2=80=94 doesn't check whether an optional contains a value; - method value =E2=80=94 throws std::bad_optional_access when an optional= =20 doesn't contain a value. In std::vector we have: - operator[] =E2=80=94 doesn't check whether a vector contains specified in= dex; - method at =E2=80=94 throws std::out_of_range when a vector doesn't contai= n=20 specified index. In std::variant we have: - ??? =E2=80=94 doesn't check whether a variant contains specified index/ty= pe; - method get =E2=80=94 throws std::bad_variant_access when a variant doesn'= t=20 contain specified index/type. Why we don't have any fast (unchecked) ways to access std::variant?=20 Assuming context when user has already checked for presence of required=20 item somehow and now needs the fastest access (i.e. he agrees to get UB=20 when absent). --=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. 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