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Groups > comp.lang.c > #123630
| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Recasting data as long ints and chars |
| Date | 2017-11-29 17:01 -0800 |
| Organization | None to speak of |
| Message-ID | <lnindsy3y6.fsf@kst-u.example.com> (permalink) |
| References | (5 earlier) <87d143k9e1.fsf@bsb.me.uk> <ovk5ev$ee3$1@dont-email.me> <87efohsxin.fsf@bsb.me.uk> <RrDMy1cnJtEcOsyJAqgdzUr1TUNmG@bongo-ra.co> <87bmjklh7u.fsf@bsb.me.uk> |
Ben Bacarisse <ben.usenet@bsb.me.uk> writes:
> Spiros Bousbouras <spibou@gmail.com> writes:
>> On Wed, 29 Nov 2017 01:07:28 +0000
>> Ben Bacarisse <ben.usenet@bsb.me.uk> wrote:
>>> unsigned nb = 0;
>>> unsigned U_ORDER = 0;
>>>
>>> and loop setting
>>>
>>> (U_ORDER << CHAR_BIT) | nb++
>>
>> If sizeof(unsigned) == 1 then U_ORDER << CHAR_BIT
>> is undefined behaviour.
>
> Why?
Because CHAR_BIT (which would have to be at least 16) would be equal to
the width of the left operand.
N1570 6.5.7p3:
The integer promotions are performed on each of the operands. The
type of the result is that of the promoted left operand. If the
value of the right operand is negative or is greater than or
equal to the width of the promoted left operand, the behavior
is undefined
> But that's a side issue.
[snip]
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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Recasting data as long ints and chars James Harris <james.harris.1@gmail.com> - 2017-11-19 21:11 +0000
Re: Recasting data as long ints and chars Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-11-23 00:50 +0000
Re: Recasting data as long ints and chars James Harris <james.harris.1@gmail.com> - 2017-11-26 15:55 +0000
Re: Recasting data as long ints and chars Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-11-26 23:55 +0000
Re: Recasting data as long ints and chars Spiros Bousbouras <spibou@gmail.com> - 2017-11-27 06:43 +0000
Re: Recasting data as long ints and chars "Pascal J. Bourguignon" <pjb@informatimago.com> - 2017-11-27 09:26 +0100
Re: Recasting data as long ints and chars Spiros Bousbouras <spibou@gmail.com> - 2017-11-27 08:50 +0000
Re: Recasting data as long ints and chars "James R. Kuyper" <jameskuyper@verizon.net> - 2017-11-27 10:35 -0500
Re: Recasting data as long ints and chars supercat@casperkitty.com - 2017-11-27 08:00 -0800
Re: Recasting data as long ints and chars "Pascal J. Bourguignon" <pjb@informatimago.com> - 2017-11-27 23:49 +0100
Re: Recasting data as long ints and chars jameskuyper@verizon.net - 2017-11-27 15:56 -0800
Re: Recasting data as long ints and chars herrmannsfeldt@gmail.com - 2017-12-15 12:45 -0800
Re: Recasting data as long ints and chars Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-11-27 15:08 +0000
Re: Recasting data as long ints and chars James Harris <james.harris.1@gmail.com> - 2017-11-27 14:55 +0000
Re: Recasting data as long ints and chars Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-11-27 15:51 +0000
Re: Recasting data as long ints and chars James Harris <james.harris.1@gmail.com> - 2017-11-28 17:13 +0000
Re: Recasting data as long ints and chars Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-11-29 01:07 +0000
Re: Recasting data as long ints and chars Spiros Bousbouras <spibou@gmail.com> - 2017-11-29 18:59 +0000
Re: Recasting data as long ints and chars Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-11-30 00:53 +0000
Re: Recasting data as long ints and chars Keith Thompson <kst-u@mib.org> - 2017-11-29 17:01 -0800
Re: Recasting data as long ints and chars Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-11-30 11:40 +0000
Re: Recasting data as long ints and chars James Harris <james.harris.1@gmail.com> - 2017-11-30 19:53 +0000
Re: Recasting data as long ints and chars Spiros Bousbouras <spibou@gmail.com> - 2017-11-29 18:37 +0000
Re: Recasting data as long ints and chars James Harris <james.harris.1@gmail.com> - 2017-11-30 22:38 +0000
Re: Recasting data as long ints and chars Spiros Bousbouras <spibou@gmail.com> - 2017-12-07 05:06 +0000
Re: Recasting data as long ints and chars supercat@casperkitty.com - 2017-12-07 07:51 -0800
Re: Recasting data as long ints and chars James Harris <james.harris.1@gmail.com> - 2017-12-08 23:14 +0000
Re: Recasting data as long ints and chars supercat@casperkitty.com - 2017-12-12 16:19 -0800
Re: Recasting data as long ints and chars Keith Thompson <kst-u@mib.org> - 2017-12-12 17:10 -0800
Re: Recasting data as long ints and chars supercat@casperkitty.com - 2017-12-13 09:02 -0800
Re: Recasting data as long ints and chars herrmannsfeldt@gmail.com - 2017-12-15 12:39 -0800
Re: Recasting data as long ints and chars Robert Wessel <robertwessel2@yahoo.com> - 2017-12-15 17:39 -0600
Re: Recasting data as long ints and chars herrmannsfeldt@gmail.com - 2017-12-15 15:52 -0800
Re: Recasting data as long ints and chars Robert Wessel <robertwessel2@yahoo.com> - 2017-12-16 00:35 -0600
Re: Recasting data as long ints and chars herrmannsfeldt@gmail.com - 2017-12-17 14:02 -0800
Re: Recasting data as long ints and chars "Chris M. Thomasson" <invalid_chris_thomasson@invalid.invalid> - 2017-12-17 15:15 -0800
Re: Recasting data as long ints and chars herrmannsfeldt@gmail.com - 2017-12-17 18:47 -0800
Re: Recasting data as long ints and chars herrmannsfeldt@gmail.com - 2017-12-17 14:09 -0800
Re: Recasting data as long ints and chars herrmannsfeldt@gmail.com - 2017-12-17 14:19 -0800
Re: Recasting data as long ints and chars herrmannsfeldt@gmail.com - 2017-12-17 14:45 -0800
Re: Recasting data as long ints and chars Spiros Bousbouras <spibou@gmail.com> - 2017-12-13 19:13 +0000
Re: Recasting data as long ints and chars James Harris <james.harris.1@gmail.com> - 2018-02-10 05:46 +0000
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