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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Can "enum" be forced to a certain "bitness"? |
| Date | 2015-09-08 16:14 -0700 |
| Organization | None to speak of |
| Message-ID | <lnio7kqza8.fsf@kst-u.example.com> (permalink) |
| References | <msnbio$t7a$1@dont-email.me> <87lhcgoh4j.fsf@bsb.me.uk> <2c4d7c17-8b7d-4ea2-aa7d-73d8de39eb49@googlegroups.com> <msnma3$cig$1@dont-email.me> <opJHx.8$FO.0@fx22.iad> |
Lew Pitcher <lew.pitcher@digitalfreehold.ca> writes:
> On Tuesday September 8 2015 18:10, in comp.lang.c, "Bartc" <bc@freeuk.com>
> wrote:
[...]
>> What type is 0 or 1? Isn't it 'int' just like the enum?
>
> No. At the /macro/ level, the argument of a define is just another token. It
> has no C type until the macro is realized.
The constants 0 and 1 are of type int.
> Or, to think of it another way, if
> #define red 0
> implies a 'type' of int on the value '0', then what sort of 'type' does
> #define FOREVER for(;;)
> imply?
0 is an expression, so it has a type, namely int. for(;;) is not an
expression, and it doesn't have a type.
>> So an enum is just a bunch of named values; it's not really a 'storage'
>> type where you need to specify a narrow int or char type or even a 2-bit
>> field.
>
> Again, I believe that you are wrong. According to the C standard,
> "An enumeration comprises a set of named integer constant values."
> where
> "An integer constant begins with a digit, but has no period or exponent
> part. It may have a prefix that specifies its base and a suffix that specifies
> its type."
> and
> "The type of an integer constant is the first of [a list of standard integer
> constant promotions] in which its value can be represented.
An "integer constant" is a specific kind of token. The "integer
constant values" of an enumeration are not syntactically "integer
constant"s.
> So, enums are indeed integer values (/named/ integer values, at that) that can
> (by use of an appropriate suffix) have the type of
> (<<unsigned>>) (<<long>> (<<long>>) ) int
No, enumeration constants are not integer constants (the standard's
wording is a bit sloppy in this area). You can't apply a "0x"
prefix to an enumeration constant to make it hexadecimal, or a "UL"
suffix to make it unsigned long.
> As for explicitly forcing an enumeration to a particular type alias (e.g.
> int16_t), that operation seems to be outside the scope of the enum keyword,
> and easily accomodated in code elsewhere.
>
> [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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Can "enum" be forced to a certain "bitness"? Ken Brody <kenbrody@spamcop.net> - 2015-09-08 15:07 -0400
Re: Can "enum" be forced to a certain "bitness"? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-08 20:17 +0100
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-08 12:36 -0700
Re: Can "enum" be forced to a certain "bitness"? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-08 22:52 +0100
Re: Can "enum" be forced to a certain "bitness"? Ken Brody <kenbrody@spamcop.net> - 2015-09-09 11:40 -0400
Re: Can "enum" be forced to a certain "bitness"? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-08 14:57 -0700
Re: Can "enum" be forced to a certain "bitness"? Bartc <bc@freeuk.com> - 2015-09-08 23:10 +0100
Re: Can "enum" be forced to a certain "bitness"? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-08 15:15 -0700
Re: Can "enum" be forced to a certain "bitness"? Ian Collins <ian-news@hotmail.com> - 2015-09-09 10:35 +1200
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-09 11:07 +0200
Re: Can "enum" be forced to a certain "bitness"? Bartc <bc@freeuk.com> - 2015-09-09 12:36 +0100
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-09 13:46 +0200
Re: Can "enum" be forced to a certain "bitness"? Ian Collins <ian-news@hotmail.com> - 2015-09-11 11:32 +1200
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-10 17:39 -0700
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-11 09:03 +0200
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-11 11:33 -0700
Re: Can "enum" be forced to a certain "bitness"? Ian Collins <ian-news@hotmail.com> - 2015-09-11 21:24 +1200
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-11 11:38 +0200
Re: Can "enum" be forced to a certain "bitness"? Richard Heathfield <rjh@cpax.org.uk> - 2015-09-11 10:40 +0100
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-11 12:51 +0200
Re: Can "enum" be forced to a certain "bitness"? Les Cargill <lcargill99@comcast.com> - 2015-09-11 12:21 -0500
Re: Can "enum" be forced to a certain "bitness"? supercat@casperkitty.com - 2015-09-11 15:03 -0700
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-12 15:01 +0200
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-11 09:23 +0200
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-10 10:06 +0200
Re: Can "enum" be forced to a certain "bitness"? David Kleinecke <dkleinecke@gmail.com> - 2015-09-15 17:55 -0700
Re: Can "enum" be forced to a certain "bitness"? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-09-08 18:36 -0400
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-08 16:14 -0700
Re: Can "enum" be forced to a certain "bitness"? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-09-08 19:49 -0400
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-08 17:20 -0700
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-08 15:48 -0700
Re: Can "enum" be forced to a certain "bitness"? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-08 16:03 -0700
Re: Can "enum" be forced to a certain "bitness"? Ian Collins <ian-news@hotmail.com> - 2015-09-09 11:16 +1200
Re: Can "enum" be forced to a certain "bitness"? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-08 16:18 -0700
Re: Can "enum" be forced to a certain "bitness"? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-08 16:19 -0700
Re: Can "enum" be forced to a certain "bitness"? Ian Collins <ian-news@hotmail.com> - 2015-09-09 11:42 +1200
Re: Can "enum" be forced to a certain "bitness"? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-09 00:52 +0100
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-09 13:28 +0200
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-09 10:56 -0700
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-09 22:17 +0200
Re: Can "enum" be forced to a certain "bitness"? Philip Lantz <prl@canterey.us> - 2015-09-08 22:06 -0700
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-08 23:14 -0700
Re: Can "enum" be forced to a certain "bitness"? supercat@casperkitty.com - 2015-09-09 16:10 -0700
Re: Can "enum" be forced to a certain "bitness"? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-09 00:42 +0100
Re: Can "enum" be forced to a certain "bitness"? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-08 16:55 -0700
Re: Can "enum" be forced to a certain "bitness"? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-09 01:31 +0100
Re: Can "enum" be forced to a certain "bitness"? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-08 17:51 -0700
Re: Can "enum" be forced to a certain "bitness"? Les Cargill <lcargill99@comcast.com> - 2015-09-08 22:53 -0500
Re: Can "enum" be forced to a certain "bitness"? Bartc <bc@freeuk.com> - 2015-09-09 10:00 +0100
Re: Can "enum" be forced to a certain "bitness"? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-09 11:27 +0100
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-09 13:31 +0200
Re: Can "enum" be forced to a certain "bitness"? Les Cargill <lcargill99@comcast.com> - 2015-09-09 18:32 -0500
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-09 17:15 -0700
Re: Can "enum" be forced to a certain "bitness"? Les Cargill <lcargill99@comcast.com> - 2015-09-09 18:29 -0500
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-09 17:10 -0700
Re: Can "enum" be forced to a certain "bitness"? Les Cargill <lcargill99@comcast.com> - 2015-09-09 22:27 -0500
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-09 21:09 -0700
Re: Can "enum" be forced to a certain "bitness"? Les Cargill <lcargill99@comcast.com> - 2015-09-10 01:54 -0500
Re: Can "enum" be forced to a certain "bitness"? Keith Thompson <kst-u@mib.org> - 2015-09-10 10:57 -0700
Re: Can "enum" be forced to a certain "bitness"? James Kuyper <jameskuyper@verizon.net> - 2015-09-10 00:21 -0400
Re: Can "enum" be forced to a certain "bitness"? Les Cargill <lcargill99@comcast.com> - 2015-09-10 02:00 -0500
Re: Can "enum" be forced to a certain "bitness"? James Kuyper <jameskuyper@verizon.net> - 2015-09-10 09:32 -0400
Re: Can "enum" be forced to a certain "bitness"? fir <profesor.fir@gmail.com> - 2015-09-09 08:19 -0700
Re: Can "enum" be forced to a certain "bitness"? fir <profesor.fir@gmail.com> - 2015-09-09 08:43 -0700
Re: Can "enum" be forced to a certain "bitness"? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-09 13:05 -0700
Re: Can "enum" be forced to a certain "bitness"? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-09 13:10 -0700
Re: Can "enum" be forced to a certain "bitness"? fir <profesor.fir@gmail.com> - 2015-09-10 00:47 -0700
Re: Can "enum" be forced to a certain "bitness"? fir <profesor.fir@gmail.com> - 2015-09-10 01:05 -0700
Re: Can "enum" be forced to a certain "bitness"? fir <profesor.fir@gmail.com> - 2015-09-10 02:04 -0700
Re: Can "enum" be forced to a certain "bitness"? Bartc <bc@freeuk.com> - 2015-09-10 10:30 +0100
Re: Can "enum" be forced to a certain "bitness"? fir <profesor.fir@gmail.com> - 2015-09-10 06:33 -0700
Re: Can "enum" be forced to a certain "bitness"? fir <profesor.fir@gmail.com> - 2015-09-10 06:43 -0700
Re: Can "enum" be forced to a certain "bitness"? fir <profesor.fir@gmail.com> - 2015-09-15 15:22 -0700
Re: Can "enum" be forced to a certain "bitness"? fir <profesor.fir@gmail.com> - 2015-09-10 01:35 -0700
Re: Can "enum" be forced to a certain "bitness"? Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-09-08 15:38 -0400
Re: Can "enum" be forced to a certain "bitness"? Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-09 10:52 -0700
Re: Can "enum" be forced to a certain "bitness"? David Thompson <dave.thompson2@verizon.net> - 2015-09-20 18:35 -0400
Re: Can "enum" be forced to a certain "bitness"? Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-26 16:30 -0700
Re: Can "enum" be forced to a certain "bitness"? Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-26 16:51 -0700
Re: Can "enum" be forced to a certain "bitness"? James Kuyper <jameskuyper@verizon.net> - 2015-09-08 15:50 -0400
Re: Can "enum" be forced to a certain "bitness"? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-09-08 20:25 +0000
Re: Can "enum" be forced to a certain "bitness"? David Brown <david.brown@hesbynett.no> - 2015-09-08 23:09 +0200
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