delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2009/04/01/09:48:51

X-Recipient: archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status: No, hits=-1.2 required=5.0 tests=AWL,BAYES_20
X-Spam-Check-By: sourceware.org
Message-ID: <432458.55204.qm@web25004.mail.ukl.yahoo.com>
Date: Wed, 1 Apr 2009 14:48:34 +0000 (GMT)
From: Marco Atzeri <marco_atzeri AT yahoo DOT it>
Subject: complex number
To: cygwin AT cygwin DOT com
MIME-Version: 1.0
X-IsSubscribed: yes
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com

Dear All,
I was trying to understand why this code

#include <iostream>
#include <complex>

int main()
{
  double a =3D 0;
  double b =3D 1. / a;
  a +=3D 1;
  std::cout << std::abs (std::complex<double> (b, a)) << '\n';
 }

produce Inf on most platform and NaN on cygwin.

I found that newlib have the function cabs (complex absolute)
but in cygwin the prototypes is

    extern double cabs();

so just a placeholder but not a useful function.
There is any reason why cygwin is missing functional
C99 complex functions ?

For what I can see mingw has not such limitation

in /usr/include/mingw/complex.h
double __MINGW_ATTRIB_CONST cabs (double _Complex);



Thanks
Marco








--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019