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From: Maciej Sobczak <no.spam@no.spam.com>
Subject: Re: Negative float problem
Date: Thu, 03 Nov 2005 16:02:05 +0100
Date: 2005-11-03T16:02:05+01:00	[thread overview]
Message-ID: <dkd8pd$6rd$1@sunnews.cern.ch> (raw)
In-Reply-To: <oq2dkd.1a7.ln@hunter.axlog.fr>

Jean-Pierre Rosen wrote:

> For example, try to find what "%" does in C/C++ (with at least one 
> negative operand, of course)...

For fundamental types, this always holds (except when b is 0):

a == (a / b) * b + a % b

If any of a or b is negative, then the sign of a % b is 
implementation-defined.

(for user-defined types - like MySuperSafeIntegerWithLotsOfChecks - it's 
of course whatever you invent it to be)

I have to admit that I was never concerned with this rule, I just don't 
divide modulo negative numbers - this kind of operation simply has no 
meaning in any of the domains where I used C/C++.


-- 
Maciej Sobczak : http://www.msobczak.com/
Programming    : http://www.msobczak.com/prog/



  reply	other threads:[~2005-11-03 15:02 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-10-26 18:32 Negative float problem Luke
2005-10-26 19:05 ` Samuel Tardieu
2005-10-26 20:42 ` Robert A Duff
2005-10-27  8:05   ` Robert I. Eachus
2005-10-27 14:48     ` Robert A Duff
2005-10-27 15:07       ` Maciej Sobczak
2005-10-27 15:47         ` Robert A Duff
2005-10-28  8:34           ` Maciej Sobczak
2005-10-29 23:39             ` Brian May
2005-10-30  9:11             ` Dmitry A. Kazakov
2005-10-31  9:46               ` Maciej Sobczak
2005-10-31 14:20                 ` Dmitry A. Kazakov
2005-11-01 11:06                   ` Maciej Sobczak
2005-11-01 14:06                     ` Robert A Duff
2005-11-01 14:46                       ` Martin Dowie
2005-11-01 16:04                         ` Hyman Rosen
2005-11-01 17:19                           ` Martin Dowie
2005-11-02  0:13                         ` Robert A Duff
2005-11-02  6:59                           ` Martin Dowie
2005-11-02 13:24                             ` Robert A Duff
2005-11-02 15:22                               ` Martin Dowie
2005-11-01 15:12                       ` Maciej Sobczak
2005-11-02  0:28                         ` Robert A Duff
2005-11-02  4:16                           ` Steve Whalen
2005-11-14  7:26                           ` Dave Thompson
2005-11-20  0:19                             ` Robert A Duff
2005-11-20 11:07                               ` Dmitry A. Kazakov
2005-11-01 14:27                     ` Dmitry A. Kazakov
2005-11-01 15:19                       ` Maciej Sobczak
2005-11-01 19:44                         ` Dmitry A. Kazakov
2005-11-02  9:04                           ` Maciej Sobczak
2005-11-02 11:17                             ` Dmitry A. Kazakov
2005-11-02 13:03                               ` Maciej Sobczak
2005-11-02 14:20                                 ` Jean-Pierre Rosen
2005-11-02 20:15                                   ` Jeffrey R. Carter
2005-11-03 13:06                                     ` Jean-Pierre Rosen
2005-11-03 18:32                                       ` Jeffrey R. Carter
2005-11-03  9:51                                   ` Maciej Sobczak
2005-11-03 13:20                                     ` Jean-Pierre Rosen
2005-11-03 15:02                                       ` Maciej Sobczak [this message]
2005-11-03 18:55                                         ` Frank J. Lhota
2005-11-04  9:32                                           ` Maciej Sobczak
2005-11-03 20:59                                     ` Simon Wright
2005-11-02 13:32                               ` Robert A Duff
2005-11-02 14:44                                 ` Dmitry A. Kazakov
2005-11-02 13:47                               ` Dmitry A. Kazakov
2005-10-27 18:33       ` Dmitry A. Kazakov
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