From -8823486549043822515 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 1149ec,c5e1f3188bfb5123 X-Google-Attributes: gid1149ec,public X-Google-Thread: f78e5,c5e1f3188bfb5123 X-Google-Attributes: gidf78e5,public From: "Clive D.W. Feather" Subject: Re: C and C++ Standard incompatibility for signed character type Date: 2000/10/17 Message-ID: #1/1 X-Deja-AN: 682620161 Approved: Fergus Henderson , moderator of comp.std.c++ References: X-Authentication-Warning: mulga.cs.mu.OZ.AU: fjh set sender to devnull@stump.algebra.com using -f X-Complaints-To: abuse@demon.net X-Mail2News-Path: news.demon.net!mulga.cs.mu.oz.au X-Trace: mail2news.demon.co.uk 971817373 mail2news:14574 mail2news mail2news.demon.co.uk Organization: Demon Internet X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) MIME-Version: 1.0 Reply-To: "Clive D.W. Feather" Newsgroups: comp.std.c++,comp.std.c In article , Jack Klein writes >Both the C99 (ISO 9899:1999) and C++ (ISO 14882:1998) are claimed to >be compatible with the original ISO C standard in terms of the >original integral types (char, short, int, long), I'm not sure what that is supposed to mean. >Both purport that descriptions of padding bits and trap >representations were allowed, just not documented, in ISO C 90. WG14, when asked detailed questions about C90, gave a set of answers. The meaning of these answers were included in the C99 review. >C++ 1998 3.9.1 paragraph 1: [...] >This rules out padding bits in signed char, but permits trap >representations. > >C99 6.2.6.2 paragraph 2: [...] >There is specifically no contrary wording for signed char, so under >this standard signed char can have both padding bits and trap >representations. Correct. This means that WG14 and WG21 made different decisions. In particular, a system with (say) 10 bit bytes might want signed char to be [-256,255]. -- Clive D.W. Feather | Internet Expert | Work: Tel: +44 20 8371 1138 | Demon Internet | Home: Fax: +44 20 8371 1037 | Thus plc | Web: Written on my laptop; please observe the Reply-To address --- [ 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://www.research.att.com/~austern/csc/faq.html ] [ Note that the FAQ URL has changed! Please update your bookmarks. ]