From 2421642048262747966 X-Google-Thread: f78e5,174aa7b34b06a51 X-Google-Attributes: gidf78e5,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local01.nntp.dca.giganews.com!nntp.speakeasy.net!news.speakeasy.net.POSTED!not-for-mail NNTP-Posting-Date: Mon, 12 Dec 2005 10:50:04 -0600 Return-Path: X-Authentication-Warning: mulga.cs.mu.OZ.AU: fjh set sender to devnull@stump.algebra.com using -f X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) Delivered-To: std-c++@ucar.edu From: "Momchil Velikov" Newsgroups: comp.std.c++ Subject: Re: Is this really unspecified behavior? Organization: http://groups.google.com Message-ID: <1134377938.542144.99440@z14g2000cwz.googlegroups.com> References: <1132759176.368850.264850@g43g2000cwa.googlegroups.com> <1132933832.802917.153350@g14g2000cwa.googlegroups.com> <1133551647.532929.325730@z14g2000cwz.googlegroups.com> <1133583412.951239.208510@g49g2000cwa.googlegroups.com> <1133910546.716987.80030@g14g2000cwa.googlegroups.com> <0l5ep1ppfhdj5p1pcu7e4na4ub0vjajlq3@4ax.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" X-Complaints-To: groups-abuse@google.com User-Agent: G2/0.2 X-HTTP-UserAgent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.10) Gecko/20050906 Firefox/1.0.6 (Debian package 1.0.6-4),gzip(gfe),gzip(gfe) Complaints-To: groups-abuse@google.com Injection-Info: z14g2000cwz.googlegroups.com; posting-host=84.22.10.178; posting-account=Fh11Bw0AAAB0-wFbEALShd0KZmegcXjp X-Virus-Scanned: amavisd-new at ucar.edu X-Virus-Scanned: amavisd-new at cs.mu.OZ.AU Approved: Fergus Henderson , moderator of comp.std.c++ X-Virus-Scanned: amavisd-new at cs.mu.OZ.AU Date: Mon, 12 Dec 2005 10:44:56 CST Lines: 41 NNTP-Posting-Host: 65.182.171.162 X-Trace: sv3-dAbZzReQsq++3iN3qfHNrvqggGYjZSdF3jZDTbZzPfONiJD53uP2Qnl6AI63iWav620ONvEeQh+/0YJ!Nyb6mE3QJvtBaKogntLg4u6rDOA2G61e9mX+QHQY/1LWd6+p90uZGLx0pJoZwJWXihckY9lC8MXr!gzzEE4YVt13FWY4qJv6NezitjWn/BeYE4b/5knTMPQ== X-Complaints-To: abuse@speakeasy.net X-DMCA-Complaints-To: abuse@speakeasy.net 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: 1.3.32 Xref: g2news1.google.com comp.std.c++:2742 "Andrei Alexandrescu See Website For Email wrote: > Momchil Velikov wrote: > > "Andrei Alexandrescu See Website For Email wrote: > > > >>So the jury is still out on finding cases (that are not source-level > >>optimizable in an obvious way) in which a specified order of argument > >>evaluation forces the compiler to generate pessimized code. > > > > How about finding cases in which the order of evaluation is not > > enforceable at the source level in an obvious way ? > > Not sure I understand. Just presenting the opposite view. I'm not sure proponents of the unspecifed evaluation order should be put in a defensive position, like your posting suggests. > For the call (expr0)(arg1, arg2, ..., argn) the > evaluation algorithm should be as if the following happens: > > 1. Evaluate expr0 resulting in a function f > 2. For each i in 1..n in this order, evaluate argi resulting in a value vi > 3. Invoke f(v1, v2, ..., vn) > > It's a pity that the intended semantics can't be easily expressed as a > source-to-source transformation. (The problem is that rvalue and lvalue > expressions would lead to different types of temporaries.) Then maybe *this* is the problem to solve. Is it related to the "forwarding problem" http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2002/n1385.htm ? ~velco --- [ 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.jamesd.demon.co.uk/csc/faq.html ]