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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: a doubt about c |
| Date | 2011-06-11 15:42 -0700 |
| Organization | None to speak of |
| Message-ID | <lnzklo7zy8.fsf@nuthaus.mib.org> (permalink) |
| References | (1 earlier) <it019r$9rg$1@dont-email.me> <4DF3AC4F.502B@mindspring.com> <it0jvq$sqo$1@dont-email.me> <0c39b7a3-d8c7-48d5-b5eb-085a3549c410@25g2000yqn.googlegroups.com> <it0mk7$cum$1@dont-email.me> |
Shao Miller <sha0.miller@gmail.com> writes:
> On 6/11/2011 4:23 PM, christian.bau wrote:
>> On Jun 11, 10:42 pm, Shao Miller<sha0.mil...@gmail.com> wrote:
>>
>>> If that conclusion holds as true and your statement that the behaviour
>>> is undefined holds as true, then I think that there could be no signed
>>> integer values that are not representable as 'signed char'. What do you
>>> think?
>>
>> It's the shift operation by itself that would be undefined. For
>> example, if int has 32 bits then any shift of a signed or unsigned int
>> by 32 or more bits is undefined. If an int has CHAR_BIT bits, then any
>> shift of a signed or unsigned int by CHAR_BIT or more bits is
>> undefined.
>
> I absolutely agree and thought that I stated as much. The point was
> that it's in a macro, so it's not 'int', it's 'intmax_t' and that means
> that 'CHAR_BIT' is not only the maximum width of any integer type, but
> the precise width of any integer type. I could be wrong about that, but
> I don't think so.
I think you're right.
The macro definition is:
#define ALL_ONES_CHAR ((1<< CHAR_BIT) - 1)
If it's used as an expression, it's of type int (because 1 is of
type int). But if it's used in the controlling expression of a #if,
it acts as if it were of type intmax_t.
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
a doubt about c Ya Shou <zxyzxy12321@gmail.com> - 2011-06-11 06:11 -0700
Re: a doubt about c James Kuyper <jameskuyper@verizon.net> - 2011-06-11 09:36 -0400
Re: a doubt about c Angel <angel+news@spamcop.net> - 2011-06-11 14:37 +0000
Re: a doubt about c Keith Thompson <kst-u@mib.org> - 2011-06-11 11:55 -0700
Re: a doubt about c Angel <angel+news@spamcop.net> - 2011-06-11 20:41 +0000
Re: a doubt about c Ian Collins <ian-news@hotmail.com> - 2011-06-12 08:58 +1200
Re: a doubt about c Shao Miller <sha0.miller@gmail.com> - 2011-06-11 17:09 -0500
Re: a doubt about c Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-11 18:25 -0400
Re: a doubt about c Ian Collins <ian-news@hotmail.com> - 2011-06-12 11:43 +1200
Re: a doubt about c Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-06-12 05:38 -0700
Re: a doubt about c Roberto Waltman <usenet@rwaltman.com> - 2011-06-12 10:12 -0400
Re: a doubt about c Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-12 10:59 -0400
Re: a doubt about c Nobody <nobody@nowhere.com> - 2011-06-15 17:07 +0100
Re: a doubt about c Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-06-12 11:33 -0700
Re: a doubt about c James Kuyper <jameskuyper@verizon.net> - 2011-06-15 09:53 -0400
Re: a doubt about c Dr Nick <3-nospam@temporary-address.org.uk> - 2011-06-16 18:46 +0100
Re: a doubt about c DSF <notavalid@address.here> - 2011-06-11 18:53 -0500
Re: a doubt about c Keith Thompson <kst-u@mib.org> - 2011-06-11 16:18 -0700
Re: a doubt about c Stephen Sprunk <stephen@sprunk.org> - 2011-06-11 21:13 -0500
Re: a doubt about c Ian Collins <ian-news@hotmail.com> - 2011-06-12 14:56 +1200
Re: a doubt about c Keith Thompson <kst-u@mib.org> - 2011-06-11 20:24 -0700
Re: a doubt about c Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-12 08:10 -0400
Re: a doubt about c Ian Collins <ian-news@hotmail.com> - 2011-06-12 11:49 +1200
Re: a doubt about c Keith Thompson <kst-u@mib.org> - 2011-06-11 15:36 -0700
Re: a doubt about c Nobody <nobody@nowhere.com> - 2011-06-12 00:23 +0100
Re: a doubt about c Seebs <usenet-nospam@seebs.net> - 2011-06-13 14:39 +0000
Re: a doubt about c Squeamizh <squeamz@hotmail.com> - 2011-06-15 15:44 -0700
Re: a doubt about c Geoff <geoff@invalid.invalid> - 2011-06-15 19:57 -0700
Re: a doubt about c "J. J. Farrell" <jjf@bcs.org.uk> - 2011-06-16 18:39 +0100
Re: a doubt about c Nobody <nobody@nowhere.com> - 2011-06-17 15:39 +0100
Re: a doubt about c Willem <willem@toad.stack.nl> - 2011-06-17 14:49 +0000
Re: a doubt about c Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-06-17 09:14 -0600
Re: a doubt about c Shao Miller <sha0.miller@gmail.com> - 2011-06-17 12:00 -0500
Re: a doubt about c Shao Miller <sha0.miller@gmail.com> - 2011-06-17 11:08 -0500
Re: [OT] Doubt vs. question. (Re: a doubt about c) Shao Miller <sha0.miller@gmail.com> - 2011-06-17 13:00 -0500
Re: [OT] Doubt vs. question. (Re: a doubt about c) Shao Miller <sha0.miller@gmail.com> - 2011-06-22 19:01 -0500
Re: a doubt about c Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-06-17 09:14 -0600
Re: a doubt about c Seebs <usenet-nospam@seebs.net> - 2011-06-17 22:16 +0000
Re: a doubt about c "J. J. Farrell" <jjf@bcs.org.uk> - 2011-06-18 02:24 +0100
Re: a doubt about c Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-06-11 23:09 -0600
[OT] Doubt vs. question. (Re: a doubt about c) Roberto Waltman <usenet@rwaltman.com> - 2011-06-12 10:05 -0400
Re: [OT] Doubt vs. question. (Re: a doubt about c) Keith Thompson <kst-u@mib.org> - 2011-06-12 11:22 -0700
Re: [OT] Doubt vs. question. (Re: a doubt about c) Ben Pfaff <blp@cs.stanford.edu> - 2011-06-12 11:44 -0700
Re: [OT] Doubt vs. question. (Re: a doubt about c) Ralph Spitzner <rasp@spitzner.org> - 2011-06-13 11:31 +0200
Re: [OT] Doubt vs. question. (Re: a doubt about c) James Kuyper <jameskuyper@verizon.net> - 2011-06-15 10:03 -0400
Re: [OT] Doubt vs. question. (Re: a doubt about c) Dr Nick <3-nospam@temporary-address.org.uk> - 2011-06-17 07:52 +0100
Re: [OT] Doubt vs. question. (Re: a doubt about c) Michael Press <rubrum@pacbell.net> - 2011-06-19 00:41 -0700
Re: [OT] Doubt vs. question. (Re: a doubt about c) James Kuyper <jameskuyper@verizon.net> - 2011-06-19 07:04 -0400
Re: [OT] Doubt vs. question. (Re: a doubt about c) Bill Waddington <william.waddington@beezmo.com> - 2011-06-23 11:03 -0700
Re: a doubt about c Shao Miller <sha0.miller@gmail.com> - 2011-06-11 11:23 -0500
Re: a doubt about c pete <pfiland@mindspring.com> - 2011-06-11 13:56 -0400
Re: a doubt about c "dr.oktopus" <blindwilly@freeonline.zzn.com> - 2011-06-11 12:53 -0700
Re: a doubt about c Lew Pitcher <lpitcher@teksavvy.com> - 2011-06-11 16:01 -0400
Re: a doubt about c Keith Thompson <kst-u@mib.org> - 2011-06-11 13:07 -0700
Re: a doubt about c Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-06-11 14:13 -0600
Re: a doubt about c Nobody <nobody@nowhere.com> - 2011-06-11 23:31 +0100
Re: a doubt about c pete <pfiland@mindspring.com> - 2011-06-11 20:07 -0400
Re: a doubt about c Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-06-11 23:05 -0600
Re: a doubt about c Shao Miller <sha0.miller@gmail.com> - 2011-06-11 16:42 -0500
Re: a doubt about c "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2011-06-11 14:23 -0700
Re: a doubt about c Shao Miller <sha0.miller@gmail.com> - 2011-06-11 17:27 -0500
Re: a doubt about c Keith Thompson <kst-u@mib.org> - 2011-06-11 15:42 -0700
Re: a doubt about c Seebs <usenet-nospam@seebs.net> - 2011-06-13 14:39 +0000
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