sizeof struct with flexible array: when did it change?

From	Kaz Kylheku <643-408-1753@kylheku.com>
Newsgroups	comp.lang.c
Subject	sizeof struct with flexible array: when did it change?
Date	2024-10-07 02:32 +0000
Organization	A noiseless patient Spider
Message-ID	<20241006192337.76@kylheku.com> (permalink)

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C99 said that the size of a structure that ends in a flexible array
member is the same as the offset of that flexible member in a
similar structure in which the array has some unspecified size.

The latest draft says that the size is calculated as if the flexible
array member were omitted, except that there may be more padding than
the omission would imply.

I can't think of a reasonable interpretation of the original
wording which would allow the size to be other than the offset
of the array, when the array is of a character type.

The current wording clearly does allow the size to go beyond the offset
in that case.

Don't get burned: don't rely on the size of a flexible array struct.
Use the offsetof that flexible member.

-- 
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sizeof struct with flexible array: when did it change? Kaz Kylheku <643-408-1753@kylheku.com> - 2024-10-07 02:32 +0000
  Re: sizeof struct with flexible array: when did it change? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-10-06 20:43 -0700
  Re: sizeof struct with flexible array: when did it change? Nick Bowler <nbowler@draconx.ca> - 2024-10-07 18:32 +0000
    Re: sizeof struct with flexible array: when did it change? Kaz Kylheku <643-408-1753@kylheku.com> - 2024-10-07 23:42 +0000
      Re: sizeof struct with flexible array: when did it change? Jeremy Brubaker <jbrubake.362@orionarts.invalid> - 2024-10-09 12:55 +0000
        Re: sizeof struct with flexible array: when did it change? scott@slp53.sl.home (Scott Lurndal) - 2024-10-09 15:06 +0000
    Re: sizeof struct with flexible array: when did it change? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-10-13 21:55 -0700

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