Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
| From | Richard Heathfield <rjh@cpax.org.uk> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: determines if it is a signed type |
| Date | 2015-05-18 20:35 +0100 |
| Organization | go, ion artisan! |
| Message-ID | <mjdero$674$1@dont-email.me> (permalink) |
| References | (1 earlier) <mjbai5$u51$1@speranza.aioe.org> <mjbtjr$db3$1@dont-email.me> <87mw12qqk7.fsf@kst-u.example.com> <mjcnfm$43l$1@dont-email.me> <87a8x253s1.fsf@kst-u.example.com> |
On 18/05/15 16:00, Keith Thompson wrote: > Richard Heathfield <rjh@cpax.org.uk> writes: >> On 18/05/15 08:43, Keith Thompson wrote: >>> Richard Heathfield <rjh@cpax.org.uk> writes: >>>> On 18/05/15 01:08, Morris Dovey wrote: >>>>> On 5/17/15 12:07 PM, asetofsymbols@gmail.com wrote: >>>>>> Is there any better way? >>>>> >>>>> Of course - look at the declaration! >>>> >>>> Or, for preference, the definition, since this will also tell you >>>> whether the object has actually been defined. >>>> >>>>> If you’re too lazy to do that, you could try (untested) >>>> >>>> If he's too lazy to look at the definition, he's probably too lazy to >>>> do something that takes effort to type and effort to think about. >>>> >>>> OP: look at the definition. Really. >>> >>> How can I portably print the value returned by time(NULL)? Looking at >>> the definition doesn't help. >> >> According to N1570, time() returns a time_t, which is a "real >> type". That means it could be an integer type or a floating point >> type. So the best we can do with time(NULL) in the absence of a time_t >> conversion specifier is to cast to the widest supported floating point >> type, presumably long double. We would do better to use gmtime or >> localtime followed by strftime to get a string in a reliable format, >> and then print that. > > Converting a long long to long double can lose information. Granted, although I must confess that I'm not terribly cut up about the fact. If the implementation is reporting a time_t so colossal that it cannot accurately be represented in a long double, then it's probably a DS9K variant anyway. > The best we can do is this: > > #include <stdio.h> > #include <time.h> > #include <stdint.h> Sorry, I thought you said "portably"? If you #include <stdint.h>, you immediately lose portability to older C implementations. I realise that this is a price you have decided you are prepared to pay, but not everyone is in that position. -- Richard Heathfield Email: rjh at cpax dot org dot uk "Usenet is a strange place" - dmr 29 July 1999 Sig line 4 vacant - apply within
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
determines if it is a signed type asetofsymbols@gmail.com - 2015-05-17 10:07 -0700
Re: determines if it is a signed type Richard Heathfield <rjh@cpax.org.uk> - 2015-05-17 18:12 +0100
Re: determines if it is a signed type asetofsymbols@gmail.com - 2015-05-17 10:34 -0700
Re: determines if it is a signed type asetofsymbols@gmail.com - 2015-05-17 11:09 -0700
Re: determines if it is a signed type Kusalananda <kusalananda@example.com> - 2015-05-17 18:22 +0000
Re: determines if it is a signed type asetofsymbols@gmail.com - 2015-05-17 11:31 -0700
Re: determines if it is a signed type Kusalananda <kusalananda@example.com> - 2015-05-17 19:59 +0000
Re: determines if it is a signed type Keith Thompson <kst-u@mib.org> - 2015-05-17 13:12 -0700
Re: determines if it is a signed type Morris Dovey <mrdovey@iedu.com> - 2015-05-17 19:08 -0500
Re: determines if it is a signed type Morris Dovey <mrdovey@iedu.com> - 2015-05-17 19:46 -0500
Re: determines if it is a signed type Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-18 01:59 +0100
Re: determines if it is a signed type Morris Dovey <mrdovey@iedu.com> - 2015-05-17 20:10 -0500
Re: determines if it is a signed type Keith Thompson <kst-u@mib.org> - 2015-05-18 00:37 -0700
Re: determines if it is a signed type Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-18 21:15 +0100
Re: determines if it is a signed type Keith Thompson <kst-u@mib.org> - 2015-05-18 15:15 -0700
Re: determines if it is a signed type glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-05-18 21:51 +0000
Re: determines if it is a signed type James Kuyper <jameskuyper@verizon.net> - 2015-05-18 18:00 -0400
Re: determines if it is a signed type glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-05-18 14:37 +0000
Re: determines if it is a signed type jacobnavia <jacob@jacob.remcomp.fr> - 2015-05-18 17:09 +0200
Re: determines if it is a signed type glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-05-18 18:14 +0000
Re: determines if it is a signed type Richard Heathfield <rjh@cpax.org.uk> - 2015-05-18 06:34 +0100
Re: determines if it is a signed type Keith Thompson <kst-u@mib.org> - 2015-05-18 00:43 -0700
Re: determines if it is a signed type Richard Heathfield <rjh@cpax.org.uk> - 2015-05-18 13:56 +0100
Re: determines if it is a signed type Keith Thompson <kst-u@mib.org> - 2015-05-18 08:00 -0700
Re: determines if it is a signed type Richard Heathfield <rjh@cpax.org.uk> - 2015-05-18 20:35 +0100
Re: determines if it is a signed type jacobnavia <jacob@jacob.remcomp.fr> - 2015-05-18 23:08 +0200
Re: determines if it is a signed type Richard Heathfield <rjh@cpax.org.uk> - 2015-05-18 22:32 +0100
Re: determines if it is a signed type jacobnavia <jacob@jacob.remcomp.fr> - 2015-05-19 00:44 +0200
Re: determines if it is a signed type Richard Heathfield <rjh@cpax.org.uk> - 2015-05-19 00:05 +0100
Re: determines if it is a signed type jacobnavia <jacob@jacob.remcomp.fr> - 2015-05-19 01:43 +0200
Re: determines if it is a signed type Richard Heathfield <rjh@cpax.org.uk> - 2015-05-19 01:08 +0100
Re: determines if it is a signed type "Bartc" <bartc@freeuk.com> - 2015-05-19 11:33 +0100
Re: determines if it is a signed type Keith Thompson <kst-u@mib.org> - 2015-05-19 08:15 -0700
Re: determines if it is a signed type "Bartc" <bartc@freeuk.com> - 2015-05-19 19:36 +0100
Re: determines if it is a signed type Keith Thompson <kst-u@mib.org> - 2015-05-19 11:55 -0700
Re: determines if it is a signed type jacobnavia <jacob@jacob.remcomp.fr> - 2015-05-19 11:39 +0200
Re: determines if it is a signed type "Bartc" <bartc@freeuk.com> - 2015-05-19 11:44 +0100
Re: determines if it is a signed type jacobnavia <jacob@jacob.remcomp.fr> - 2015-05-19 12:11 +0200
Re: determines if it is a signed type jadill33@gmail.com - 2015-05-19 05:45 -0700
Re: determines if it is a signed type Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-19 15:03 +0100
Re: determines if it is a signed type jadill33@gmail.com - 2015-05-19 08:46 -0700
Re: determines if it is a signed type Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-19 17:08 +0100
Re: determines if it is a signed type jadill33@gmail.com - 2015-05-19 09:52 -0700
Re: determines if it is a signed type Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-19 20:36 +0100
Re: determines if it is a signed type jadill33@gmail.com - 2015-05-20 07:40 -0700
Re: determines if it is a signed type Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-20 23:12 +0100
Re: determines if it is a signed type jadill33@gmail.com - 2015-05-21 13:52 -0700
Re: determines if it is a signed type Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-21 22:48 +0100
Re: determines if it is a signed type jadill33@gmail.com - 2015-05-22 05:50 -0700
Re: determines if it is a signed type Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-22 23:14 +0100
Re: determines if it is a signed type jadill33@gmail.com - 2015-05-26 14:31 -0700
Re: determines if it is a signed type Tim Rentsch <txr@alumni.caltech.edu> - 2015-05-22 23:32 -0700
Re: determines if it is a signed type David Brown <david.brown@hesbynett.no> - 2015-05-20 12:26 +0200
Re: determines if it is a signed type Richard Heathfield <rjh@cpax.org.uk> - 2015-05-19 15:28 +0100
Re: determines if it is a signed type raltbos@xs4all.nl (Richard Bos) - 2015-05-23 10:37 +0000
Re: determines if it is a signed type Keith Thompson <kst-u@mib.org> - 2015-05-18 15:21 -0700
Re: determines if it is a signed type Richard Heathfield <rjh@cpax.org.uk> - 2015-05-19 00:04 +0100
Re: determines if it is a signed type Keith Thompson <kst-u@mib.org> - 2015-05-19 08:03 -0700
Re: determines if it is a signed type David Brown <david.brown@hesbynett.no> - 2015-05-19 08:47 +0200
Re: determines if it is a signed type Keith Thompson <kst-u@mib.org> - 2015-05-19 08:07 -0700
Re: determines if it is a signed type James Kuyper <jameskuyper@verizon.net> - 2015-05-18 11:28 -0400
Re: determines if it is a signed type Keith Thompson <kst-u@mib.org> - 2015-05-18 00:40 -0700
csiph-web