From 3391803039365598153 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,53d56717e82ab663 X-Google-Attributes: gidf78e5,public From: Anders Pytte Subject: Re: cout << null pointers Date: 2000/07/08 Message-ID: #1/1 X-Deja-AN: 643682295 Content-transfer-encoding: 7BIT Approved: Fergus Henderson , moderator of comp.std.c++ References: <39656D42.E049FCAA@ix.netcom.com> X-Authentication-Warning: mulga.cs.mu.OZ.AU: fjh set sender to devnull@stump.algebra.com using -f Content-Type: text/plain; charset=US-ASCII X-Complaints-To: abuse@demon.net X-Mail2News-Path: news.demon.net!mulga.cs.mu.oz.au X-Trace: mail2news.demon.co.uk 962999385 mail2news:18249 mail2news mail2news.demon.co.uk X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) User-Agent: Microsoft-Outlook-Express-Macintosh-Edition/5.02.2022 MIME-version: 1.0 NNTP-posting-date: Fri, 07 Jul 2000 15:40:47 EDT Newsgroups: comp.std.c++ in article 39656D42.E049FCAA@ix.netcom.com, Paul Meyerholtz at pholtz@ix.netcom.com wrote on 7/8/00 5:08 AM: > I have found an inconsistent output by various compilers of the following: > > char * p = 0; > cout * q = ""; > > cout << p << "\n\n"; > cout << q; > > Most compilers seem to handle "cout << q" without a problem. (But I > have heard that Visual C++ 6 fails this test). > > However, the handling of "cout << p" seems to cause problems for most > computers, with results from segment faults to garbage output. > (CodeWarrior for the Mac, which I use, outputs a couple of garbage > characters, but always the same ones). > > Why is the output of p and q different? In the above, "cout << p" says, print the c string stored at address 0, while "cout << q" says, print a c string of zero length. Why should these produce the same output? > Is there anything in the standard about this? Should cout check for the > null pointer? Perhaps, but that is not how it is defined. Actually, I'm not aware of any standard functions that take char* as an input and that check for null. This appears to be the responsibility of the caller :-) Anders. -- Anders Pytte Milkweed Software PO Box 32 voice: (802) 586-2545 Craftsbury, VT 05826 email: anders@milkweed.com --- [ 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 ]