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Groups > comp.lang.c > #102784
| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Dinamic array without malloc - Can be done? |
| Date | 2017-01-30 11:35 -0800 |
| Organization | None to speak of |
| Message-ID | <ln60kwbasv.fsf@kst-u.example.com> (permalink) |
| References | (5 earlier) <8087f1de-3ea6-f75e-5c3b-a64efe6a7d84@verizon.net> <ln60lfhn8w.fsf@kst-u.example.com> <kfneg03ljm0.fsf@x-alumni2.alumni.caltech.edu> <lno9z7fvl4.fsf@kst-u.example.com> <kfninowhfbk.fsf@x-alumni2.alumni.caltech.edu> |
Tim Rentsch <txr@alumni.caltech.edu> writes:
> Keith Thompson <kst-u@mib.org> writes:
>> Tim Rentsch <txr@alumni.caltech.edu> writes:
>>> Keith Thompson <kst-u@mib.org> writes:
>>>> In C99, complex types are mandatory, but the <complex.h> header
>>>> is required only for hosted implementations. That meant that a
>>>> freestanding implementation must support the types _Complex
>>>> float, _Complex double, and _Complex long double, but without
>>>> <complex.h> there's no portable way to specify the value of i.
>>>
>>> What isn't portable about this?
>>>
>>> typedef _Complex float Zfloat;
>>>
>>> Zfloat
>>> imaginary_unit(){
>>> return (union {float f[2]; Zfloat z;}){ {0,1} }.z;
>>> }
>>
>> OK, no *clean* portable way.
>
> I'm not sure if this response is meant to be funny, but if it
> isn't, what isn't clean about this way of providing i? It can't
> be used to initialize file scope or static varibles, but other
> than that what's wrong with it? (I'm assuming the function would
> be defined as 'static inline' if that were thought important.)
The language provides complex types, but the core language
doesn't provide a direct way to specify the value of i, the most
fundamental mathematical complex constant that isn't a real number.
A function that takes advantage of an incidental guarantee about
the *representation* of complex types to construct the value of i
is clever and useful, but IMHO it's hardly clean. (Perhaps that
guarantee is intended to permit this kind of thing.)
IMHO the language *should* have provided a simpler way to specify
the value of i. Perhaps the semantics of compound literals could
have been extended to permit complex values, such as
(float _Complex){0.0, 1.0};
Imagine a language that provides floating-point types but has no
way to write a constant expression with the value -1.0. Some kind
of union hack that fiddles with the sign bit might be workable,
but I'd hardly consider it satisfactory.
> Note by the way that freestanding implementations are not obliged
> to support complex types, even in C99, by virtue of section 4 p6.
Ah, you're right, I missed that. That blows most of my argument
out of the water. Any C99 conforming hosted implementation (and
any C11 conforming hosted implementation that doesn't predefine
__STDC_NO_COMPLEX__) must support both the _Complex keyword and
the _Complex_I macro, so it's not as bad as I thought it was.
I suppose my remaining objection is mainly esthetic.
--
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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Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-15 08:45 -0800
Re: Dinamic array without malloc - Can be done? BartC <bc@freeuk.com> - 2017-01-15 16:53 +0000
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-15 09:34 -0800
Re: Dinamic array without malloc - Can be done? BartC <bc@freeuk.com> - 2017-01-17 21:09 +0000
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-17 13:45 -0800
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-17 14:09 -0800
Re: Dinamic array without malloc - Can be done? BartC <bc@freeuk.com> - 2017-01-17 22:41 +0000
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-17 15:06 -0800
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-17 16:49 -0800
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-17 16:56 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-17 20:37 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-18 09:38 +0100
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-31 08:49 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-31 10:39 -0800
Re: Dinamic array without malloc - Can be done? luser droog <luser.droog@gmail.com> - 2017-01-31 10:55 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-31 11:40 -0800
Re: Dinamic array without malloc - Can be done? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-01-31 10:57 -0800
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-03 23:06 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-15 10:42 -0800
Re: Dinamic array without malloc - Can be done? BartC <bc@freeuk.com> - 2017-01-15 20:15 +0000
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-15 12:43 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-15 15:08 -0800
Re: Dinamic array without malloc - Can be done? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-01-15 12:25 -0500
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-15 10:46 -0800
Re: Dinamic array without malloc - Can be done? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-15 20:13 +0000
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-15 15:06 -0800
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-15 12:46 -0800
Re: Dinamic array without malloc - Can be done? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-01-15 16:10 -0500
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 20:37 -0800
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-15 21:02 -0800
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-30 04:23 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-16 09:05 +0100
Re: Dinamic array without malloc - Can be done? Ian Collins <ian-news@hotmail.com> - 2017-01-16 21:16 +1300
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-16 09:48 +0100
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-15 09:29 -0800
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-15 09:37 -0800
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-15 09:56 -0800
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-15 10:34 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-15 10:48 -0800
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-15 11:10 -0800
Re: Dinamic array without malloc - Can be done? Jean-Marc Bourguet <jm@bourguet.org> - 2017-01-15 20:22 +0100
Re: Dinamic array without malloc - Can be done? Chad <cdalten@gmail.com> - 2017-01-15 11:50 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-15 15:12 -0800
Re: Dinamic array without malloc - Can be done? Richard Heathfield <rjh@cpax.org.uk> - 2017-01-15 17:50 +0000
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-15 10:38 -0800
Re: Dinamic array without malloc - Can be done? Richard Heathfield <rjh@cpax.org.uk> - 2017-01-15 19:34 +0000
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-15 12:51 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-15 13:10 -0800
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-15 16:23 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-15 18:08 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-16 09:56 +0100
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-16 08:35 -0800
Re: Dinamic array without malloc - Can be done? "Chris M. Thomasson" <invalid@invalid.invalid> - 2017-01-16 11:07 -0800
Re: Dinamic array without malloc - Can be done? "Chris M. Thomasson" <invalid@invalid.invalid> - 2017-01-16 11:17 -0800
Re: Dinamic array without malloc - Can be done? Robert Wessel <robertwessel2@yahoo.com> - 2017-01-16 15:21 -0600
Re: Dinamic array without malloc - Can be done? "Chris M. Thomasson" <invalid@invalid.invalid> - 2017-01-31 22:22 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-17 00:22 +0100
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-16 16:23 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-17 02:04 +0100
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-16 17:27 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-17 09:16 +0100
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 20:32 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-16 10:02 +0100
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-16 09:22 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-17 00:25 +0100
Re: Dinamic array without malloc - Can be done? Barry Schwarz <schwarzb@dqel.com> - 2017-01-15 11:53 -0800
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-15 12:22 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-15 15:32 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-15 16:01 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-16 10:19 +0100
Re: Dinamic array without malloc - Can be done? BartC <bc@freeuk.com> - 2017-01-16 11:28 +0000
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-16 14:29 +0100
Re: Dinamic array without malloc - Can be done? BartC <bc@freeuk.com> - 2017-01-16 15:41 +0000
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-16 17:27 +0100
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-16 07:56 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-16 17:31 +0100
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-16 08:48 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-17 00:29 +0100
Re: Dinamic array without malloc - Can be done? "Chris M. Thomasson" <invalid@invalid.invalid> - 2017-01-16 11:25 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-16 12:28 -0800
Re: Dinamic array without malloc - Can be done? "Chris M. Thomasson" <invalid@invalid.invalid> - 2017-01-16 12:38 -0800
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-15 16:57 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-16 00:37 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-16 10:23 +0100
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-16 01:35 -0800
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-16 09:15 -0800
Re: Dinamic array without malloc - Can be done? BartC <bc@freeuk.com> - 2017-01-16 01:29 +0000
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-16 10:08 +0100
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-16 08:08 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-17 00:35 +0100
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-16 16:31 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-17 09:27 +0100
Re: Dinamic array without malloc - Can be done? BartC <bc@freeuk.com> - 2017-01-17 12:11 +0000
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-17 14:23 +0100
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-17 05:38 -0800
Re: Dinamic array without malloc - Can be done? BartC <bc@freeuk.com> - 2017-01-17 14:17 +0000
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-17 07:09 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-17 05:14 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-17 14:40 +0100
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-17 06:41 -0800
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-17 16:00 +0100
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-17 07:45 -0800
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-17 08:18 -0800
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-17 08:27 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-17 09:29 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-17 09:23 -0800
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-17 10:35 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-17 12:41 -0800
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-17 13:45 -0800
Re: Dinamic array without malloc - Can be done? Robert Wessel <robertwessel2@yahoo.com> - 2017-01-17 21:00 -0600
Re: Dinamic array without malloc - Can be done? fir <profesor.fir@gmail.com> - 2017-01-15 11:55 -0800
Re: Dinamic array without malloc - Can be done? Siri Cruise <chine.bleu@yahoo.com> - 2017-01-15 14:59 -0800
Re: Dinamic array without malloc - Can be done? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-15 20:04 +0000
Re: Dinamic array without malloc - Can be done? David Brown <david.brown@hesbynett.no> - 2017-01-15 21:33 +0100
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-15 13:00 -0800
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 20:27 -0800
Re: Dinamic array without malloc - Can be done? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-01-15 16:34 -0500
Re: Dinamic array without malloc - Can be done? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-01-15 16:43 -0500
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-15 16:17 -0800
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 20:22 -0800
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-15 21:00 -0800
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-30 05:01 -0800
Re: Dinamic array without malloc - Can be done? Keith Thompson <kst-u@mib.org> - 2017-01-30 11:35 -0800
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-01 16:18 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-02-01 16:37 -0800
Re: Dinamic array without malloc - Can be done? Robert Wessel <robertwessel2@yahoo.com> - 2017-02-01 23:21 -0600
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-02 00:27 -0800
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-02-02 10:58 -0800
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-03 22:51 -0800
Re: Dinamic array without malloc - Can be done? "Chris M. Thomasson" <invalid@invalid.invalid> - 2017-01-15 15:41 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-15 15:44 -0800
Re: Dinamic array without malloc - Can be done? "Chris M. Thomasson" <invalid@invalid.invalid> - 2017-01-15 16:17 -0800
Re: Dinamic array without malloc - Can be done? Alla _ <modelling.data@gmail.com> - 2017-01-16 01:47 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-16 01:50 -0800
Re: Dinamic array without malloc - Can be done? Alla _ <modelling.data@gmail.com> - 2017-01-16 02:38 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-16 03:15 -0800
Re: Dinamic array without malloc - Can be done? Alla _ <modelling.data@gmail.com> - 2017-01-16 03:40 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-16 04:21 -0800
Re: Dinamic array without malloc - Can be done? Alla _ <modelling.data@gmail.com> - 2017-01-16 04:29 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-16 04:36 -0800
Re: Dinamic array without malloc - Can be done? Richard Heathfield <rjh@cpax.org.uk> - 2017-01-16 11:36 +0000
Re: Dinamic array without malloc - Can be done? Alla _ <modelling.data@gmail.com> - 2017-01-16 03:44 -0800
Re: Dinamic array without malloc - Can be done? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-16 15:34 +0000
Re: Dinamic array without malloc - Can be done? Richard Heathfield <rjh@cpax.org.uk> - 2017-01-16 16:01 +0000
Re: Dinamic array without malloc - Can be done? John Bode <jfbode1029@gmail.com> - 2017-01-17 10:14 -0800
Re: Dinamic array without malloc - Can be done? James Kuyper <jameskuyper@verizon.net> - 2017-01-17 13:21 -0500
Re: Dinamic array without malloc - Can be done? John Bode <jfbode1029@gmail.com> - 2017-01-17 11:43 -0800
Re: Dinamic array without malloc - Can be done? James Kuyper <jameskuyper@verizon.net> - 2017-01-17 15:07 -0500
Re: Dinamic array without malloc - Can be done? supercat@casperkitty.com - 2017-01-17 12:24 -0800
Re: Dinamic array without malloc - Can be done? "Fernando D. Bozzo" <fdbozzo@gmail.com> - 2017-01-17 10:24 -0800
Re: Dinamic array without malloc - Can be done? Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-30 05:21 -0800
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