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Re: C declarations

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From Keith Thompson <kst-u@mib.org>
Newsgroups comp.lang.c
Subject Re: C declarations
Date Mon, 30 Jan 2017 11:42:57 -0800
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David Brown <david.brown@hesbynett.no> writes:
> On 30/01/17 14:00, BartC wrote:
[...]
>> Then there is this, also outside a function, although more compilers
>> complain about it:
>> 
>>   *p = 10;
>> 
>> This presumably declares p to be of type int*, and initialises it to 10.
>
> Again, I believe it is legal syntax in C90.  It has undefined behaviour
> (due to the conversion from an integer).

I believe it's legal syntax, but it's a constraint violation.  There is
no implicit conversion from int to int* (other than the special case of
a null pointer constant).

Pre-ANSI C compilers commonly permitted implicit conversions between
pointers and integers, but C89/C90 did not.

[...]

-- 
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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C declarations BartC <bc@freeuk.com> - 2017-01-30 13:00 +0000
  Re: C declarations David Brown <david.brown@hesbynett.no> - 2017-01-30 14:25 +0100
    Re: C declarations Keith Thompson <kst-u@mib.org> - 2017-01-30 11:42 -0800
  Re: C declarations Andrey Tarasevich <andreytarasevich@hotmail.com> - 2017-01-31 13:46 -0800
    Re: C declarations BartC <bc@freeuk.com> - 2017-01-31 22:13 +0000
      Re: C declarations Andrey Tarasevich <andreytarasevich@hotmail.com> - 2017-01-31 16:43 -0800
        Re: C declarations Andrey Tarasevich <andreytarasevich@hotmail.com> - 2017-01-31 17:06 -0800
      Re: C declarations Ian Collins <ian-news@hotmail.com> - 2017-02-01 17:58 +1300
        Re: C declarations luser droog <luser.droog@gmail.com> - 2017-01-31 22:42 -0800
          Re: C declarations Ian Collins <ian-news@hotmail.com> - 2017-02-01 19:48 +1300
            Re: C declarations Robert Wessel <robertwessel2@yahoo.com> - 2017-02-01 01:18 -0600
            Re: C declarations David Brown <david.brown@hesbynett.no> - 2017-02-01 10:10 +0100
              Re: C declarations BartC <bc@freeuk.com> - 2017-02-01 11:39 +0000
                Re: C declarations David Brown <david.brown@hesbynett.no> - 2017-02-01 13:55 +0100
                Re: C declarations BartC <bc@freeuk.com> - 2017-02-01 13:22 +0000
                Re: C declarations David Brown <david.brown@hesbynett.no> - 2017-02-01 16:30 +0100
                Re: C declarations Keith Thompson <kst-u@mib.org> - 2017-02-01 08:15 -0800
                Re: C declarations supercat@casperkitty.com - 2017-02-01 08:44 -0800
                Re: C declarations David Brown <david.brown@hesbynett.no> - 2017-02-01 20:56 +0100
                Re: C declarations supercat@casperkitty.com - 2017-02-01 08:29 -0800
                Re: C declarations BartC <bc@freeuk.com> - 2017-02-01 17:24 +0000
                Re: C declarations fir <profesor.fir@gmail.com> - 2017-02-01 09:55 -0800
                Re: C declarations BartC <bc@freeuk.com> - 2017-02-01 18:44 +0000
                Re: C declarations Keith Thompson <kst-u@mib.org> - 2017-02-01 11:03 -0800
                Re: C declarations fir <profesor.fir@gmail.com> - 2017-02-01 12:26 -0800
                Re: C declarations fir <profesor.fir@gmail.com> - 2017-02-01 13:03 -0800
                Re: C declarations fir <profesor.fir@gmail.com> - 2017-02-01 13:12 -0800
                Re: C declarations fir <profesor.fir@gmail.com> - 2017-02-03 16:07 -0800
                Re: C declarations Keith Thompson <kst-u@mib.org> - 2017-02-01 10:44 -0800
                Re: C declarations jameskuyper@verizon.net - 2017-02-01 11:08 -0800
                Re: C declarations Keith Thompson <kst-u@mib.org> - 2017-02-01 10:40 -0800
                Re: C declarations BartC <bc@freeuk.com> - 2017-02-01 17:04 +0000
                Re: C declarations Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-01 19:58 +0000
                Re: C declarations BartC <bc@freeuk.com> - 2017-02-01 21:23 +0000
                Re: C declarations Keith Thompson <kst-u@mib.org> - 2017-02-01 08:08 -0800
                Re: C declarations Andrey Tarasevich <andreytarasevich@hotmail.com> - 2017-02-01 12:45 -0800
  Re: C declarations Andrey Tarasevich <andreytarasevich@hotmail.com> - 2017-03-06 11:19 -0800
    Re: C declarations Keith Thompson <kst-u@mib.org> - 2017-03-06 11:27 -0800

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