From: Corinna Vinschen <corinna-cygwin@cygwin.com>
To: cygwin@cygwin.com
Subject: Re: strtod ("nan") returns negative NaN
Date: Tue, 14 Aug 2018 15:54:00 -0000 [thread overview]
Message-ID: <20180814153528.GY3747@calimero.vinschen.de> (raw)
In-Reply-To: <1e04c237-70f8-5cc9-7dae-d00e3bfea39d@avenger.ws>
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On Aug 14 12:20, Heavenly Avenger wrote:
> On 8/14/2018 10:23 AM, Corinna Vinschen wrote:
> > I just wonder why returning -NaN when the input is "-nan" isn't the
> > better approach. After all:
> >
> > printf ("nan (\"\") = %f\n", nan (""));
> > printf ("-nan (\"\") = %f\n", -nan (""));
> >
> > ==>
> >
> > nan ("") = nan
> > -nan ("") = -nan
> >
> > So, shouldn't the ideal outcome be this:
> >
> > strtod ("nan", NULL) = nan
> > strtod ("-nan", NULL) = -nan
> > strtold ("nan", NULL) = nan
> > strtold ("-nan", NULL) = -nan
> >
> > ?
> >
> > Corinna
> >
> I'd say it is not the better/best approach as, even though it makes sense,
> all other implementations or linux distributions treat it as a plain "nan".
> So anything written for linux will potentially break on cygwin, I am not
> sure this is the idea behind cygwin, right?
My point is, even the glibc printf prints a negative NaN as "-nan",
see above. strtod/strtold returning a different NaN value looks
inconsistent.
Well, never mind.
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Maintainer cygwin AT cygwin DOT com
Red Hat
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next prev parent reply other threads:[~2018-08-14 15:35 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-13 15:16 `std::stod ("nan")` " Masamichi Hosoda
2018-08-13 16:53 ` Stephen John Smoogen
2018-08-13 23:46 ` Duncan Roe
2018-08-14 0:46 ` Stephen John Smoogen
2018-08-14 1:10 ` Masamichi Hosoda
2018-08-14 2:31 ` strtod ("nan") returns negative NaN (was `std::stod ("nan")` returns negative NaN) Masamichi Hosoda
2018-08-14 3:25 ` strtod ("nan") returns negative NaN Steven Penny
2018-08-14 4:46 ` Masamichi Hosoda
2018-08-14 9:56 ` Corinna Vinschen
2018-08-14 10:39 ` Corinna Vinschen
2018-08-14 12:18 ` Masamichi Hosoda
2018-08-14 13:23 ` Corinna Vinschen
2018-08-14 13:41 ` Stephen John Smoogen
2018-08-14 15:25 ` Heavenly Avenger
2018-08-14 15:54 ` Corinna Vinschen [this message]
2018-08-14 17:08 ` Heavenly Avenger
2018-08-14 16:05 ` Masamichi Hosoda
2018-08-14 19:24 ` Steven Penny
2018-08-14 21:45 ` Andy Moreton
2018-08-14 22:23 ` Stephen John Smoogen
2018-08-15 0:02 ` Eric Blake
2018-08-15 7:36 ` Steven Penny
2018-08-21 3:18 ` Brian Inglis
2018-08-14 19:44 ` Achim Gratz
2018-08-21 13:28 ` Brian Inglis
2018-08-14 15:05 ` Masamichi Hosoda
2018-08-14 15:21 ` Masamichi Hosoda
2018-08-14 15:35 ` Heavenly Avenger
2018-08-14 20:05 ` Joseph Myers
2018-08-14 20:19 ` Joseph Myers
2018-08-15 8:51 ` Masamichi Hosoda
2018-08-15 12:55 ` Masamichi Hosoda
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