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Groups > comp.lang.c > #6709

Re: int * vs char *

From Ian Collins <ian-news@hotmail.com>
Newsgroups comp.lang.c
Subject Re: int * vs char *
Date 2011-06-23 20:11 +1200
Message-ID <96gaqtFmo4U1@mid.individual.net> (permalink)
References <itr3lm$i8j$1@speranza.aioe.org> <lnliwuiz7c.fsf@nuthaus.mib.org> <its93d$62e$1@dont-email.me> <kfntybhasbp.fsf@x-alumni2.alumni.caltech.edu>

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On 06/23/11 08:02 PM, Tim Rentsch wrote:
> Noob<root@127.0.0.1>  writes:
>
>> Keith Thompson wrote:
>>
>>> Even if you corrected the type mismatch by writing:
>>>
>>> char *s = "hello";
>>>       *s = 'w';
>>>
>>> your program's behavior would be undefined.  s points to a string
>>> literal (more precisely, it points to the first element of the static
>>> array associated with the string literal), and any attempt to modify a
>>> string literal has undefined behavior.
>>
>> Since modifying a character string literal already has UB in
>> the current standard, then why doesn't the next standard
>> specify that string literal have type const char[] instead
>> of just char[] ?
>
> Because the cost is large and the benefit is small.

The benefit can be the difference between something failing to compile 
or failing horribly at run time.

> I daresay it's pretty easy to get diagnostics for
> non-const uses of string literals if one wants
> them.  Given that, there is no compelling reason
> to force everyone to change, especially since it
> can be useful for an implementation to define
> string literals so that they are usefully writeable.

Under what circumstances?

-- 
Ian Collins

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Thread

int * vs char * yugandhar <nospam@nospam.com> - 2011-06-21 21:49 +0000
  Re: int * vs char * John Gordon <gordon@panix.com> - 2011-06-21 21:58 +0000
    Re: int * vs char * "Morris Keesan" <mkeesan@post.harvard.edu> - 2011-06-21 20:25 -0400
  Re: int * vs char * Ian Collins <ian-news@hotmail.com> - 2011-06-22 09:59 +1200
  Re: int * vs char * Ike Naar <ike@sverige.freeshell.org> - 2011-06-21 22:18 +0000
  Re: int * vs char * Shao Miller <sha0.miller@gmail.com> - 2011-06-21 18:34 -0500
  Re: int * vs char * Keith Thompson <kst-u@mib.org> - 2011-06-21 15:42 -0700
    Re: int * vs char * Noob <root@127.0.0.1> - 2011-06-22 10:28 +0200
      Re: int * vs char * Shao Miller <sha0.miller@gmail.com> - 2011-06-22 05:23 -0500
      Re: int * vs char * James Kuyper <jameskuyper@verizon.net> - 2011-06-22 06:25 -0400
        Re: int * vs char * Ian Collins <ian-news@hotmail.com> - 2011-06-23 07:56 +1200
          Re: int * vs char * Shao Miller <sha0.miller@gmail.com> - 2011-06-22 18:12 -0500
            Re: int * vs char * Ian Collins <ian-news@hotmail.com> - 2011-06-23 10:23 +1200
            Re: int * vs char * Keith Thompson <kst-u@mib.org> - 2011-06-22 17:23 -0700
              Re: int * vs char * Ian Collins <ian-news@hotmail.com> - 2011-06-23 12:54 +1200
                Re: int * vs char * Keith Thompson <kst-u@mib.org> - 2011-06-22 18:18 -0700
                Re: int * vs char * Ian Collins <ian-news@hotmail.com> - 2011-06-23 13:23 +1200
              Re: int * vs char * Shao Miller <sha0.miller@gmail.com> - 2011-06-24 15:39 -0400
                Re: int * vs char * Ian Collins <ian-news@hotmail.com> - 2011-06-25 09:28 +1200
                Re: int * vs char * Keith Thompson <kst-u@mib.org> - 2011-06-24 14:58 -0700
                Re: int * vs char * Ian Collins <ian-news@hotmail.com> - 2011-06-25 10:06 +1200
                Re: int * vs char * Shao Miller <sha0.miller@gmail.com> - 2011-06-26 15:44 -0500
                Re: int * vs char * Keith Thompson <kst-u@mib.org> - 2011-06-24 14:29 -0700
                Re: int * vs char * Ian Collins <ian-news@hotmail.com> - 2011-06-25 09:36 +1200
                Re: int * vs char * Shao Miller <sha0.miller@gmail.com> - 2011-06-26 16:24 -0500
                Re: int * vs char * Tim Rentsch <txr@alumni.caltech.edu> - 2011-06-25 08:39 -0700
            Re: int * vs char * gordonb.5qick@burditt.org (Gordon Burditt) - 2011-06-22 23:49 -0500
      Re: int * vs char * Stephen Sprunk <stephen@sprunk.org> - 2011-06-22 11:31 -0500
        Re: int * vs char * gordonb.idn9q@burditt.org (Gordon Burditt) - 2011-06-23 00:45 -0500
          Re: int * vs char * pacman@kosh.dhis.org (Alan Curry) - 2011-06-23 20:08 +0000
          Re: int * vs char * Stephen Sprunk <stephen@sprunk.org> - 2011-06-23 22:40 -0500
            Re: int * vs char * Ian Collins <ian-news@hotmail.com> - 2011-06-24 15:46 +1200
              Re: int * vs char * Stephen Sprunk <stephen@sprunk.org> - 2011-06-24 09:24 -0500
                Re: int * vs char * Shao Miller <sha0.miller@gmail.com> - 2011-07-04 18:00 -0400
                Re: int * vs char * Dr Nick <3-nospam@temporary-address.org.uk> - 2011-07-05 07:45 +0100
                Re: int * vs char * Harald van Dijk <truedfx@gmail.com> - 2011-07-05 10:39 -0700
                Re: int * vs char * Shao Miller <sha0.miller@gmail.com> - 2011-07-05 14:09 -0400
                Re: int * vs char * Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-07-07 21:56 +0300
                Re: int * vs char * Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-07-08 02:46 +0300
                Re: int * vs char * Shao Miller <sha0.miller@gmail.com> - 2011-07-07 22:26 -0400
                Re: int * vs char * Stephen Sprunk <stephen@sprunk.org> - 2011-07-07 22:41 -0500
                Re: int * vs char * "Joel C. Salomon" <joelcsalomon@gmail.com> - 2011-07-05 15:32 -0400
                Re: int * vs char * Shao Miller <sha0.miller@gmail.com> - 2011-07-06 09:58 -0400
      Re: int * vs char * Tim Rentsch <txr@alumni.caltech.edu> - 2011-06-23 01:02 -0700
        Re: int * vs char * Ian Collins <ian-news@hotmail.com> - 2011-06-23 20:11 +1200
          Re: int * vs char * Tim Rentsch <txr@alumni.caltech.edu> - 2011-06-25 09:23 -0700
            Re: int * vs char * Keith Thompson <kst-u@mib.org> - 2011-06-25 12:37 -0700
              Re: int * vs char * Tim Rentsch <txr@alumni.caltech.edu> - 2011-06-27 11:40 -0700
  Re: int * vs char * Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-21 21:46 -0400
    Re: int * vs char * "Kleuskes & Moos" <kleuske@xs4all.nl> - 2011-06-22 10:06 -0700
      Re: int * vs char * Keith Thompson <kst-u@mib.org> - 2011-06-22 13:06 -0700
        Re: int * vs char * "Kleuskes & Moos" <kleuske@xs4all.nl> - 2011-06-22 13:29 -0700
  Re: int * vs char * Stephen Sprunk <stephen@sprunk.org> - 2011-06-21 21:29 -0500

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