From 1682498436446284955 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,9723061da44e5214 X-Google-Attributes: gidf78e5,public From: postmast.root.admi.gov@iname.com (blargg) Subject: Re: Exception while throwing an exception? Date: 1999/09/07 Message-ID: #1/1 X-Deja-AN: 522297647 Approved: Fergus Henderson References: <37D3E50E.A13D8AFC@prodigy.net> <37D56411.F9600F29@ibm.net> X-Original-Date: Tue, 07 Sep 1999 17:23:49 -0500 X-Complaints-To: news@news.unimelb.edu.au X-Trace: ariel.ucs.unimelb.edu.au 936743863 9057 128.250.37.153 (7 Sep 1999 22:37:43 GMT) Organization: e-mail address IS valid - but fools the spammers X-Auth: PGPMoose V1.1 PGP comp.std.c++ iQBFAgUAN9WTpOEDnX0m9pzZAQH0kwF+I07MjMWXjSV/NokC4tPR0dIsIrvnd4Xq cvSlpV9v66kAa8D3FRQF0dIHClMTnC/m =A4Lu NNTP-Posting-Date: 7 Sep 1999 22:37:43 GMT Newsgroups: comp.std.c++ In article <37D56411.F9600F29@ibm.net>, b_thomas@ibm.net wrote: > Siemel B. Naran wrote: > > > > On 6 Sep 1999 20:53:57 GMT, Andy Larson wrote: > > > > >What is the required behavior when the constructor of an exception > > >object throws an exception? For example, if an exception is thrown as > > >in > > > > The required behaviour is a call to std::terminate(). > > I can't find such a specification in the standard. Can you tell where > you found it? In the section describing std::terminate() (15.5.1) > > Coding guideline: try to make your exception objects not throw. > > To avoid risking to throw an out-of-memory or std::bad_alloc, > > avoid dynamic memory in the exception object. > > > > Coding guideline: try to make your destructors of exception as > > well as non-exception objects not throw. If an object is being > > destroyed because of an exception already in progress, then if > > the destructor throws, we have two exceptions. The result is a > > call to std::terminate(). > > Agreed with the guidelines. But, the standard specifying so is a bit > extreme. What do you think should be specified instead? As it says in the introduction for std::terminate, "In the following situations exception handling must be abandoned for less subtle error handling techniques." Bjarne also discusses this reasoning in C++PL 2nd on page 322, C++PL 3rd page 373 (specifically addressing exceptions in destructors), and on page 383 (essentially the same discussion mentioned above as in C++PL 2nd) If you want something different to happen in this case, you are certainly free to handle it differently yourself (within the constraints of the language). I see exceptions as being, at the core, a non-local goto (without any type information). The type information is an extra benefit that can be handled explicitly in some other fashion by the programmer. --- [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://reality.sgi.com/austern_mti/std-c++/faq.html ]