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Re: Array-as-pointer Syntax

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On 29/03/2019 08:09, James Kuyper wrote:
> On Thursday, March 28, 2019 at 1:23:26 PM UTC-4, Ian Collins wrote:
>> On 29/03/2019 06:04, David T. Ashley wrote:
>>> Given:
>>>
>>>     int x[1000];
>>>
>>> what is the difference between:
>>>
>>>      memset(x, 0, sizeof(x));
>>>
>>> and
>>>
>>>      memset(&x, 0, sizeof(x));
>>>
>>> I would think there is NO difference, but I might be missing something ...
>>
>> Check for yourself!
>>
>> #include <stdio.h>
>>
>> int main()
>> {
>>     int x[111];
>>     printf( "%p %p\n", x, &x);
> 
> Not quite correct. When you pass a %p format specifier to printf(), "The
> corresponding argument "shall be a pointer to a pointer to void."
> (7.21.6.2p12).
> 
> You're quite likely to get away with this mistake - on many systems all
> pointers (or at least, all pointers to objects) have the same
> representation, so it doesn't matter if you pass a pointer of the wrong
> type. However, for maximum portability you should cast to void*:
> 
>      printf("%p %p\n", (void*)x, (void*)&x);

It was a quick test...

-- 
Ian.

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Array-as-pointer Syntax "David T. Ashley" <dashley@gmail.com> - 2019-03-28 10:04 -0700
  Re: Array-as-pointer Syntax Bart <bc@freeuk.com> - 2019-03-28 17:18 +0000
    Re: Array-as-pointer Syntax David Brown <david.brown@hesbynett.no> - 2019-03-28 21:31 +0100
  Re: Array-as-pointer Syntax Ian Collins <ian-news@hotmail.com> - 2019-03-29 06:23 +1300
    Re: Array-as-pointer Syntax James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-03-28 12:09 -0700
      Re: Array-as-pointer Syntax Ian Collins <ian-news@hotmail.com> - 2019-03-29 08:21 +1300
      Re: Array-as-pointer Syntax Ike Naar <ike@iceland.freeshell.org> - 2019-03-28 22:59 +0000
        Re: Array-as-pointer Syntax James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-03-28 17:44 -0700
    Re: Array-as-pointer Syntax Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-03-28 20:12 +0000
  Re: Array-as-pointer Syntax James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-03-28 11:57 -0700
    Re: Array-as-pointer Syntax Keith Thompson <kst-u@mib.org> - 2019-03-28 13:57 -0700
      Re: Array-as-pointer Syntax James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-03-28 19:50 -0400
  Re: Array-as-pointer Syntax Keith Thompson <kst-u@mib.org> - 2019-03-28 14:04 -0700
  Re: Array-as-pointer Syntax John Bode <jfbode1029@gmail.com> - 2019-03-29 07:24 -0700
    Re: Array-as-pointer Syntax Ike Naar <ike@iceland.freeshell.org> - 2019-03-29 18:08 +0000

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