220 33504 article Path: news.gmane.org!.POSTED!not-for-mail From: david.bolvansky@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Catch block for multiple exceptions Date: Tue, 1 Aug 2017 10:04:21 -0700 (PDT) Lines: 247 Approved: news@gmane.org Message-ID: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_2652_308856715.1501607061056" X-Trace: blaine.gmane.org 1501607066 18152 195.159.176.226 (1 Aug 2017 17:04:26 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 1 Aug 2017 17:04:26 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBDSMRTMFUIFRBFPJQLGAKGQEEDI4EDI@isocpp.org Tue Aug 01 19:04:19 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-qk0-f197.google.com ([209.85.220.197]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dcaaf-0004HX-2f for gclcip-std-proposals@m.gmane.org; Tue, 01 Aug 2017 19:04:17 +0200 Original-Received: by mail-qk0-f197.google.com with SMTP id i143sf10287512qke.14 for ; Tue, 01 Aug 2017 10:04:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:message-id:subject:mime-version:x-original-sender :reply-to:precedence:mailing-list:list-id:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=B/SNUAzcNILv2asCPpdFgWI2t0NtIo77MYmAGS5kNRg=; b=C6FeP9jAZVWsAkLxD6Z5OE1E5xwPmn1RTwSJoAzPhZwn+SB6RnnMJMmetEh7sEPL2o NfOi8Zi9XSux3Ngb5lTv6eTNfzUCksCSBpsHavWuJjp1VhDfVgBFF6lRUYRRkG9YinPB bkNarKahdTfbsDpcQ7562G2WoLtM4wwXZOXonU63YvW85EF8WblnYP3dPQLNyQzenKUr I+UFi/xeOPyYEO3tuRaVJWLj6pPm+FkazWZfKNcJ1kdwQkigTSQkQuBugTxCZfqDW6Ur fxLfpuvoLEP6UQhSCacCMn2v/rAyQvhgdYzzKTyPd4UntFCBhF/49OwTdZy5emzWbGz4 Sh9Q== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:message-id:subject:mime-version:x-original-sender :reply-to:precedence:mailing-list:list-id:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=B/SNUAzcNILv2asCPpdFgWI2t0NtIo77MYmAGS5kNRg=; b=dowKuECsAUlchL9YkQBiK6DEY9oSY+63xk3T1Vk6k7PW/QP4Wih+LykW0aDH7AzVI9 1bZXKG7aJki2nK3P/OJq6I5am8p9qTJsvOuU5AZWODZDsGTWO1c/IFwpegTh//GMSZyh mD3F0jQgqS7HDcgAHuXR6q2SKwXbjJOHmZrcURl57ZGNZlG47wFyI4rurRjxNXs3OXwP +Nes08rwad3UerbeGvl+w70IVH7SaiaQfy6eFyO+wN0NH4fN2mTg1fffC2BVBkbnhyxI cwFIWCqhwwsjhNli8lWkLEoanzL4NnXVrQKkApe3/Mh98f6Q5NsqFQVRgaCNFJ3N3LNV tnsQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:message-id:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=B/SNUAzcNILv2asCPpdFgWI2t0NtIo77MYmAGS5kNRg=; b=aF5dVTdWrX8UFhfEPyd3HhUpFsyKAak8NINkGqfvHT+SZEVZyVRpnQqqwX3BTvmmrp kSsET1U1bSMdPM7QWoZAClgcRwqLBcxV9wK6PSxWEPwJi9Djd9ej8c0j1U+dKMNCGHUx kK6nmpH216YchOtjLTjHnmbziLk5QXG4xzlgLFo68HUQggsEj/1WEBxOWzTWLecPnqxV RmMNJkwjzq9H3D+wHmgGK2T7hz1iciqicqS0jaem2/GulTHGAx1DeG31HIM6gNM4xXt0 49lccTaE/uGvT86WZEWl7NsTeYO148a1wWogjFPQdWooPLzI0o/6i1YVZ73VwGTgsh6j DF0w== X-Gm-Message-State: AIVw112k1dqapXZfsv30Op9QLTuw8guTPo2gvAwHgbmvWUIluFdeQQNl CCdNDezJn00Szdz3 X-Received: by 10.237.59.44 with SMTP id p41mr13993599qte.49.1501607062768; Tue, 01 Aug 2017 10:04:22 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.36.108.4 with SMTP id w4ls1639149itb.12.canary-gmail; Tue, 01 Aug 2017 10:04:21 -0700 (PDT) X-Received: by 10.31.59.134 with SMTP id i128mr106187vka.29.1501607061402; Tue, 01 Aug 2017 10:04:21 -0700 (PDT) X-Original-Sender: david.bolvansky@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:33504 Archived-At: ------=_Part_2652_308856715.1501607061056 Content-Type: multipart/alternative; boundary="----=_Part_2653_1000255546.1501607061056" ------=_Part_2653_1000255546.1501607061056 Content-Type: text/plain; charset="UTF-8" If you need to handle multiple exceptions you write catch block per every exception. Example: try { ... } catch (exceptionA e) { // handle expetionA f(); } } catch (exceptionB e) { // handle exceptionB f(); } } catch (exceptionC e) { // handle exceptionC f(); } } catch (exceptionD e) { // handle exceptionD g(); } If e.g. exception A, B, C could be handled via the same logic (e.g function "f"), we are copy-pasting exception-handling code (callinf f() in this case) in particular catch blocks. To avoid that, proposed improvment could be: try { ... } catch (exceptionA, exceptionB, exceptionC) { // handle exception (does not matter whether exception A, B or C - we have same handling code for them) f(); } } catch (exceptionD e) { // handle exceptionD g(); } With the instance of one of those exceptions: catch (exceptionA, exceptionB, exceptionC e) { f(e); } -- 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/effe744d-f832-42c7-9b2a-ef31551067d0%40isocpp.org. ------=_Part_2653_1000255546.1501607061056 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
If you need to handle multiple exceptions you write catch = block per every exception.

Example:

try {
=C2=A0 =C2=A0 =C2=A0 ...
} catch (exceptionA e) {
=C2=A0 =C2=A0 =C2=A0= // handle = expetionA<= br>=C2=A0 =C2=A0 =C2=A0f();
}

=
} catch (exceptionB e) {
=C2=A0 =C2=A0 =C2=A0// handle exceptionB
=C2=A0 =C2=A0 =C2=A0f();
}


} catch (exceptionC e) {
=C2=A0 =C2=A0 =C2=A0// handle exceptionC
=C2=A0 = =C2=A0 =C2=A0f();}<= span style=3D"color: #000;" class=3D"styled-by-prettify">


} catch (exceptionD e) {
=C2= =A0 =C2=A0 =C2=A0// handle exceptionD
=C2=A0 =C2=A0 =C2=A0g();
}




If e.g. exception A, B, C could be handled via the same logic (e.g = function "f"), we are copy-pasting exception-handling code (calli= nf f() in this case) in particular catch blocks.

<= br>
To avoid that, proposed improvment could be:


try {
=C2=A0 =C2=A0 =C2=A0 ...
} catch (exceptionA, exceptionB, exceptionC) {
=C2=A0 =C2=A0 =C2=A0// handle exception (does not matter whe= ther exception A, B or C - we have same handling code for them)
=C2=A0 =C2=A0 =C2= =A0f();
}

} catch (exceptionD e) = {
=C2=A0 =C2=A0 = =C2=A0// h= andle exceptionD
=C2=A0 =C2=A0 =C2=A0g();
}<= br>



Wit= h the instance of one of =C2=A0those exceptions:
catch (exceptionA, exceptionB, exceptionC e) {=
=C2=A0 =C2=A0= f(e);
}



=

--
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To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposa= ls+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/effe744d-f832-42c7-9b2a-ef31551067d0= %40isocpp.org.
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