From 5924359441147282395 X-Google-Thread: f78e5,82cd3599ce330676 X-Google-NewGroupId: yes X-Google-Attributes: gid7894ca11fe,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news1.google.com!Xl.tags.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local2.nntp.dca.giganews.com!news.giganews.com.POSTED!not-for-mail NNTP-Posting-Date: Sun, 04 Apr 2010 12:10:04 -0500 Return-Path: To: (Usenet) From: Kazutoshi Satoda Newsgroups: comp.std.c++ Subject: Re: throwing in a noexcept(true) function Organization: unknown Sender: cppmods@cs.rpi.edu Approved: james.dennett@gmail.com Message-ID: <4BB73613.2040903@f2.dion.ne.jp> References: <4BB4D8B0.3070603@f2.dion.ne.jp> Content-Type: text/plain; charset=UTF-8; format=flowed X-Original-Date: Sat, 03 Apr 2010 21:35:31 +0900 X-Submission-Address: std-c++@netlab.cs.rpi.edu Date: Sun, 4 Apr 2010 12:04:30 CST Lines: 62 X-Usenet-Provider: http://www.giganews.com X-Trace: sv3-zYtc9gFXlUoPcyxzC1GehwET9sf6dKDjvXJzvcrLqlrwpE+XUkVHqS9MSbN5zkSHs1A8u6u7FMZpe/M!V2SglHUVhHePN+s4IWeIza8X2YjK9ncmjYT0ZW1V3v+HmvjeMse7+MVJ X-Complaints-To: abuse@giganews.com X-DMCA-Notifications: http://www.giganews.com/info/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Xref: g2news2.google.com comp.std.c++:2369 Herb Sutter wrote: > > The trouble with (d) is that then you get all the problems > Java gets with statically checked exceptions, I re-read some articles about what was wrong with checked exceptions. http://www.artima.com/intv/handcuffsP.html http://googletesting.blogspot.com/2009/09/checked-exceptions-i-love-you-but-you.html For all problems written there, I thought they won't be problems with noexcept because noexcept is not the default and not written for specific types. > that scheme doesn't work at all with templates (what exactly would you > write?) Like this: template > class vector { ... iterator erase(const_iterator position) noexcept( has_nothrow_copy_constructor::value && has_nothrow_move_constructor::value && has_nothrow_copy_assign::value && has_nothrow_move_assign::value) For vector::erase(), we have now the following specification. Throws: Nothing unless an exception is thrown by the copy constructor, move constructor, assignment operator, or move assignment operator of T. The above declaration looks very straightforward based on this specification. It will give a compile error when erase() is called in a noexcept(true) function with T which doesn't fulfill the above conditions. That sounds fine and great. > and even when it does work more often than not quickly devolves into the > meaningless "throw(exception)". I don't think this will be a problem in C++ since such "throw(exception)" specification is the default (no exceptions specification). This is very different situation than that in Java. Programmers won't be forced to write exception specifications until they write static exception specification for their own function, or they pass a type for a template which has a static exception specification. > As often as I hear a C++ programmer > wish their exception specifications had Java's static semantics, I > hear a Java programmer wish theirs had non-static semantics. Static checking with noexcept is very different with Java's static checking, in that is default or not, that is a type list or a binary. I think the problem should be reconsidered separately, shouldn't it? -- k_satoda [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@netlab.cs.rpi.edu] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://www.comeaucomputing.com/csc/faq.html ]