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Re: C11 6.3.2.3p7 Referenced Type

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On 04/01/2013 2:08 AM, Shao Miller wrote:
...

>    "A pointer to an object type may be converted to a pointer to a
> different object type. If the resulting pointer is not correctly
> aligned) for the referenced type, the behavior is undefined.

What I don't like about this wording (both old and new) is that it talks 
about the alignment of the *resulting* pointer, even though the standard 
does not generally specify what the result of the conversion is (other 
than that it's a pointer that can be converted back; a few exceptions 
include conversions to char*, between pointers to a struct and to the 
type of its first member, etc.).  Would it be wrong to say, instead, 
that the behaviour is undefined if the *original* pointer, the one 
before the conversion, is not correctly aligned for the type referenced 
by the type of the result?  Or to say, separately, that if the original 
pointer satisfies the alignment requirements of some type, then the 
converted pointer satisfies them too?

Or maybe even that the converted pointer points at the same byte in 
memory than the original pointer did (using some more formal wording)? 
I've seen claims that this follows from some other requirements of the 
standard (C99 at the time), but I never managed to find them.

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C11 6.3.2.3p7 Referenced Type Shao Miller <sha0.miller@gmail.com> - 2013-01-04 02:08 -0500
  Re: C11 6.3.2.3p7 Referenced Type Keith Thompson <kst-u@mib.org> - 2013-01-04 08:09 -0800
    Re: C11 6.3.2.3p7 Referenced Type Shao Miller <sha0.miller@gmail.com> - 2013-01-04 12:25 -0500
    Re: C11 6.3.2.3p7 Referenced Type lawrence.jones@siemens.com - 2013-01-04 13:47 -0500
      Re: C11 6.3.2.3p7 Referenced Type Shao Miller <sha0.miller@gmail.com> - 2013-01-04 14:56 -0500
        Re: C11 6.3.2.3p7 Referenced Type lawrence.jones@siemens.com - 2013-01-04 17:10 -0500
          Re: C11 6.3.2.3p7 Referenced Type Shao Miller <sha0.miller@gmail.com> - 2013-01-04 20:34 -0500
  Re: C11 6.3.2.3p7 Referenced Type Wojtek Lerch <wojtek_l@yahoo.ca> - 2013-01-04 23:45 -0500
    Re: C11 6.3.2.3p7 Referenced Type Shao Miller <sha0.miller@gmail.com> - 2013-01-05 02:07 -0500
      Re: C11 6.3.2.3p7 Referenced Type Shao Miller <sha0.miller@gmail.com> - 2013-01-05 02:16 -0500
    Re: C11 6.3.2.3p7 Referenced Type Tim Rentsch <txr@alumni.caltech.edu> - 2013-01-06 17:25 -0800
      Re: C11 6.3.2.3p7 Referenced Type Wojtek Lerch <wojtek_l@yahoo.ca> - 2013-01-06 22:13 -0500
        Re: C11 6.3.2.3p7 Referenced Type Shao Miller <sha0.miller@gmail.com> - 2013-01-06 23:30 -0500
          Re: C11 6.3.2.3p7 Referenced Type Wojtek Lerch <wojtek_l@yahoo.ca> - 2013-01-07 00:07 -0500
            Re: C11 6.3.2.3p7 Referenced Type Shao Miller <sha0.miller@gmail.com> - 2013-01-07 01:29 -0500
              Re: C11 6.3.2.3p7 Referenced Type Shao Miller <sha0.miller@gmail.com> - 2013-01-07 02:18 -0500
              Re: C11 6.3.2.3p7 Referenced Type Wojtek Lerch <wojtek_l@yahoo.ca> - 2013-01-10 17:45 -0500
          Re: C11 6.3.2.3p7 Referenced Type Tim Rentsch <txr@alumni.caltech.edu> - 2013-01-06 22:30 -0800
            Re: C11 6.3.2.3p7 Referenced Type Shao Miller <sha0.miller@gmail.com> - 2013-01-07 01:58 -0500
              Re: C11 6.3.2.3p7 Referenced Type Tim Rentsch <txr@alumni.caltech.edu> - 2013-01-06 23:16 -0800
        Re: C11 6.3.2.3p7 Referenced Type Tim Rentsch <txr@alumni.caltech.edu> - 2013-01-06 22:02 -0800

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