Re: is there a way to ask a variable what it is?

Path	csiph.com!xmission!nnrp.xmission!.POSTED.shell.xmission.com!not-for-mail
From	nobody@example.org (Scott)
Newsgroups	comp.lang.c
Subject	Re: is there a way to ask a variable what it is?
Date	Thu, 30 Jan 2020 15:59:55 GMT
Organization	XMission http://xmission.com/
Message-ID	<5e32fa92.4262077640@core> (permalink)
References	<r0qtkb$3qj$1@dont-email.me> <87lfpqrkit.fsf@bsb.me.uk> <r0r17d$jbq$1@dont-email.me> <87blqmqdek.fsf@bsb.me.uk> <variable-20200129214811@ram.dialup.fu-berlin.de> <emmYF.251862$_R5.228244@fx19.am4>
Injection-Info	news.xmission.com; posting-host="shell.xmission.com:2607:fa18:0:beef::4"; logging-data="17389"; mail-complaints-to="abuse@xmission.com"
X-Newsreader	Forte Free Agent 1.21/32.243
Xref	csiph.com comp.lang.c:149532

Show key headers only | View raw

On Wed, 29 Jan 2020 20:58:47 +0000, Bart <bc@freeuk.com> wrote:

>On 29/01/2020 20:49, Stefan Ram wrote:
>> Ben Bacarisse <ben.usenet@bsb.me.uk> writes:
>>> Let me illustrate.  If knowing the type is the top-level goal, the
>>> answer is simple: you can't.
>> 
>>    Knowing the type of a variable?
>> 
>>    It can be read from the declaration.
>> 
>>    For example,
>> 
>> double c;
>> 
>>    The type of »c« is double.
>
>
>That's a simple example. Try:
>
>    clock_t c;
>
>What's is the actual type of c? Or a little more challenging:

I have one (silly) answer.

$cat tmp.c
#include <stdio.h>
int main(void) {
	clock_t x;
	printf("%c\n", x);
}

$gcc -Wformat tmp.c
tmp.c: In function 'main':
tmp.c:4:18: warning: format '%c' expects argument of type 'int', but
argument 2 has type 'clock_t {aka long unsigned int}' [-Wformat=]
         printf("%c\n", x);
                 ~^
                 %ld


There, clock_t is long unsigned. I don't have any idea how to do this
at runtime, or with any other compiler.

Thread

is there a way to ask a variable what it is? T <T@invalid.invalid> - 2020-01-28 19:19 -0800
  Re: is there a way to ask a variable what it is? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-01-29 03:47 +0000
    Re: is there a way to ask a variable what it is? T <T@invalid.invalid> - 2020-01-28 20:20 -0800
      Re: is there a way to ask a variable what it is? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-01-29 19:18 +0000
        Re: is there a way to ask a variable what it is? Bart <bc@freeuk.com> - 2020-01-29 20:58 +0000
          Re: is there a way to ask a variable what it is? nobody@example.org (Scott) - 2020-01-30 15:59 +0000
            Re: is there a way to ask a variable what it is? scott@slp53.sl.home (Scott Lurndal) - 2020-01-30 16:35 +0000
    Re: is there a way to ask a variable what it is? Siri Cruise <chine.bleu@yahoo.com> - 2020-01-28 21:55 -0800
      Re: is there a way to ask a variable what it is? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-01-30 00:24 +0000
        solved: Re: is there a way to ask a variable what it is? T <T@invalid.invalid> - 2020-01-29 21:51 -0800
          Re: solved: Re: is there a way to ask a variable what it is? fir <profesor.fir@gmail.com> - 2020-01-30 03:16 -0800
  Re: is there a way to ask a variable what it is? Ian Collins <ian-news@hotmail.com> - 2020-01-29 17:28 +1300
    Re: is there a way to ask a variable what it is? T <T@invalid.invalid> - 2020-01-28 20:55 -0800
      Re: is there a way to ask a variable what it is? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-01-29 06:49 +0000
      Re: is there a way to ask a variable what it is? Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-29 08:08 +0100
      Re: is there a way to ask a variable what it is? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-01-30 00:14 +0000
        solved: Re: is there a way to ask a variable what it is? T <T@invalid.invalid> - 2020-01-29 21:51 -0800
        Re: is there a way to ask a variable what it is? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-02-18 08:56 -0800
          Re: is there a way to ask a variable what it is? already5chosen@yahoo.com - 2020-02-19 01:19 -0800
            Re: is there a way to ask a variable what it is? chad <cdalten@gmail.com> - 2020-02-19 02:53 -0800
            Re: is there a way to ask a variable what it is? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-02-19 12:45 +0000
            Re: is there a way to ask a variable what it is? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-19 07:55 -0500
            Re: is there a way to ask a variable what it is? Bart <bc@freeuk.com> - 2020-02-19 13:02 +0000
              Re: is there a way to ask a variable what it is? chad <cdalten@gmail.com> - 2020-02-19 07:27 -0800
            Re: is there a way to ask a variable what it is? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-02-22 09:42 -0800
  Re: is there a way to ask a variable what it is? Robert Wessel <robertwessel2@yahoo.com> - 2020-01-28 22:36 -0600
    Re: is there a way to ask a variable what it is? T <T@invalid.invalid> - 2020-01-28 20:55 -0800
      Re: is there a way to ask a variable what it is? Manfred <noname@add.invalid> - 2020-01-29 13:22 +0100
        Re: is there a way to ask a variable what it is? David Brown <david.brown@hesbynett.no> - 2020-01-29 13:57 +0100
          Re: is there a way to ask a variable what it is? Manfred <noname@add.invalid> - 2020-01-29 17:47 +0100
            Re: is there a way to ask a variable what it is? David Brown <david.brown@hesbynett.no> - 2020-01-30 12:06 +0100
    Re: is there a way to ask a variable what it is? scott@slp53.sl.home (Scott Lurndal) - 2020-01-29 15:10 +0000
      Re: is there a way to ask a variable what it is? Manfred <noname@add.invalid> - 2020-01-29 17:07 +0100
  Re: is there a way to ask a variable what it is? Siri Cruise <chine.bleu@yahoo.com> - 2020-01-28 21:52 -0800
  Re: is there a way to ask a variable what it is? Bart <bc@freeuk.com> - 2020-01-29 11:11 +0000
    Re: is there a way to ask a variable what it is? Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-29 13:30 +0100
      Re: is there a way to ask a variable what it is? Bart <bc@freeuk.com> - 2020-01-29 12:44 +0000
        Re: is there a way to ask a variable what it is? Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-29 14:03 +0100
          Re: is there a way to ask a variable what it is? gazelle@shell.xmission.com (Kenny McCormack) - 2020-01-29 14:03 +0000
          Re: is there a way to ask a variable what it is? Bart <bc@freeuk.com> - 2020-01-29 14:30 +0000
            Re: is there a way to ask a variable what it is? Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-29 15:45 +0100
              Re: is there a way to ask a variable what it is? Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-29 16:28 +0100
                Re: is there a way to ask a variable what it is? T <T@invalid.invalid> - 2020-01-29 08:35 -0800
                Re: is there a way to ask a variable what it is? Bart <bc@freeuk.com> - 2020-01-29 17:34 +0000
                Re: is there a way to ask a variable what it is? Bonita Montero <Bonita.Montero@gmail.com> - 2020-01-29 18:48 +0100
    Re: is there a way to ask a variable what it is? Thiago Adams <thiago.adams@gmail.com> - 2020-01-29 04:43 -0800
      Re: is there a way to ask a variable what it is? David Brown <david.brown@hesbynett.no> - 2020-01-29 14:46 +0100
        Re: is there a way to ask a variable what it is? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-01-29 15:15 +0000
          Re: is there a way to ask a variable what it is? fir <profesor.fir@gmail.com> - 2020-01-29 08:11 -0800
          Re: is there a way to ask a variable what it is? T <T@invalid.invalid> - 2020-01-29 08:38 -0800
  Re: is there a way to ask a variable what it is? Bart <bc@freeuk.com> - 2020-01-29 11:23 +0000
  Re: is there a way to ask a variable what it is? John Bode <jfbode1029@gmail.com> - 2020-01-29 11:55 -0800
  Re: is there a way to ask a variable what it is? jacobnavia <jacob@jacob.remcomp.fr> - 2020-02-19 12:23 +0100
  Re: is there a way to ask a variable what it is? jacobnavia <jacob@jacob.remcomp.fr> - 2020-02-19 12:23 +0100

csiph-web