From -7025312961410109298 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,7b33df5790e7ad92 X-Google-Attributes: gidf78e5,public From: Gabriel Dos_Reis Subject: Re: complex design flaw (#1) Date: 1999/03/15 Message-ID: #1/1 X-Deja-AN: 455095825 X-NNTP-Posting-Host: korrigan.inria.fr Content-Transfer-Encoding: 8bit Approved: stephen.clamage@sun.com (comp.std.c++) References: <01be6e30$aeae59e0$7d9cd4c7@danielp.interlog.com> X-UID: 0000000001 X-Status: $$$T Content-Type: text/plain; charset=iso-8859-1 Organization: I.N.R.I.A Sophia-Antipolis (France) Mime-Version: 1.0 Newsgroups: comp.std.c++ Originator: clamage@taumet "Daniel Parker" writes: | Gabriel Dos_Reis wrote in article | ... | > | > nbecker@fred.net writes: | > | > So initialiation of a vector or | > a valarray of complex may be result in a memset(). | | Incidently, I'm a little rusty on the bit layout of a floating point | number; can I rely on | | double x = 0.0; | double y; | | memset( &y, 0, sizeof(double) ); | | x == y ? On most plateforms and with serious C++ implementations (for example those that adhere to IEEE-754), the answer is unambiguously *yes*. IEEE-754 and LIA-1 require (-0 == +0) to evaluate to true. | memcmp( &x, &y, sizeof(double) ) == 0 ? yes (again under the previous assumptions). -- Gabriel Dos Reis, dosreis@cmla.ens-cachan.fr [ 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 ]