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Re: what is the difference between these statement

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Ben Bacarisse <ben.usenet@bsb.me.uk> writes:

> Dr Nick <3-nospam@temporary-address.org.uk> writes:
> <snip>
>> To try to turn this into something constructive.  Are there any
>> circumstances in which casting the argument to a ctype function to
>> unsigned char would cause problems (apart from doing it before checking
>> for EOF - like "toupper(getchar())").
>>
>> I can't think of one.
>
> I can only think of very contrived situations that rely on the
> distinction between conversion and re-interpretation on machines with
> odd number representations.  And in these situations I think a case can
> be made that the problem lies elsewhere.
>
> BTW, a plausible "EOF" example would be:
>
>   int c;
>   while (isspace(c = getchar())); /* skip space */

Even in that case,
   while (isspace((unsigned char)(c = getchar()))); /* skip space */
isn't going to do any harm.  'c' still holds the uncast EOF and can be
tested for later.  

Except in a pathological case where EOF cast to unsigned char turns into
a space character I suppose - could that actually happen?
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what is the difference between these statement ashu <ashishmourya21@gmail.com> - 2012-05-06 04:11 -0700
  Re: what is the difference between these statement Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-06 12:29 +0100
    Re: what is the difference between these statement ashu <ashishmourya21@gmail.com> - 2012-05-06 07:56 -0700
    Re: what is the difference between these statement ashu <ashishmourya21@gmail.com> - 2012-05-06 08:01 -0700
      Re: what is the difference between these statement Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-06 18:54 +0100
  Re: what is the difference between these statement Dr Nick <3-nospam@temporary-address.org.uk> - 2012-05-06 15:39 +0100
    Re: what is the difference between these statement Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-06 18:32 +0100
      Re: what is the difference between these statement Dr Nick <3-nospam@temporary-address.org.uk> - 2012-05-06 19:23 +0100
        Re: what is the difference between these statement Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-06 22:52 +0100
          Re: what is the difference between these statement Dr Nick <3-nospam@temporary-address.org.uk> - 2012-05-07 08:08 +0100
            Re: what is the difference between these statement Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-07 12:44 +0100
              Re: what is the difference between these statement Dr Nick <3-nospam@temporary-address.org.uk> - 2012-05-09 06:54 +0100
                Re: what is the difference between these statement James Kuyper <jameskuyper@verizon.net> - 2012-05-09 07:46 -0400
                Re: what is the difference between these statement Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-09 15:32 +0100
                Re: what is the difference between these statement Tim Rentsch <txr@alumni.caltech.edu> - 2012-05-09 12:02 -0700
                Re: what is the difference between these statement jgk@panix.com (Joe keane) - 2012-05-10 17:46 +0000
                Re: what is the difference between these statement Keith Thompson <kst-u@mib.org> - 2012-05-10 11:47 -0700
                Re: what is the difference between these statement Tim Rentsch <txr@alumni.caltech.edu> - 2012-05-11 08:55 -0700
                Re: what is the difference between these statement jgk@panix.com (Joe keane) - 2012-05-13 20:09 +0000
                Re: what is the difference between these statement Kaz Kylheku <kaz@kylheku.com> - 2012-05-13 23:24 +0000
                Re: what is the difference between these statement Tim Rentsch <txr@alumni.caltech.edu> - 2012-05-14 11:46 -0700

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