Path: csiph.com!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Keith Thompson Newsgroups: comp.lang.c Subject: Re: Is 'extern' necessary? Date: Sat, 11 Feb 2017 10:19:16 -0800 Organization: None to speak of Lines: 28 Message-ID: References: <4920b63e-c9ac-4ddb-96f4-5c45257f6689@googlegroups.com> <37272c08-9e01-4fb8-bcc5-6e63e0e723d6@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: mx02.eternal-september.org; posting-host="5b75f8dd226436b078478393b0f38f01"; logging-data="20250"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18MJjolUhG62kH+OI4aqgSR" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) Cancel-Lock: sha1:XpL9Z+n9eJiUgTChs/IDwGR9qO0= sha1:E15iLNXJxzmZmxlYTVCGDnyXHqM= Xref: csiph.com comp.lang.c:103689 supercat@casperkitty.com writes: > On Friday, February 10, 2017 at 9:33:12 PM UTC-6, james...@verizon.net wrote: >> One of the most >> common things that happens when the behavior is undefined, is that the code >> works exactly the way that the author incorrectly thought it was required to >> work. > > An even more common thing that happens when code executes behavior which is > not defined by the Standard is that it will work in a predictable fashion > which is defined by the target implementation, even if behavior would be > unpredictable on other implementations. That's a subset of what James described (assuming that by "required" he meant "required by the C standard", which I'm fairly sure he did). > One of the biggest problems with C is that there hasn't been any effort to > formally characterize classes of implementations which support useful > guarantees beyond those required by the Standard. POSIX is one such effort. [...] -- Keith Thompson (The_Other_Keith) kst-u@mib.org Working, but not speaking, for JetHead Development, Inc. "We must do something. This is something. Therefore, we must do this." -- Antony Jay and Jonathan Lynn, "Yes Minister"