"struct hack" with non-character array[1]

From	Hallvard B Furuseth <h.b.furuseth@usit.uio.no>
Newsgroups	comp.lang.c
Subject	"struct hack" with non-character array[1]
Date	2011-08-19 12:28 +0200
Organization	University of Oslo, Norway
Message-ID	<hbf.20110819eide@bombur.uio.no> (permalink)

Show all headers | View raw

I seem to remember the "struct hack" is safer if the fake
dynamic array has character type.  If that's right, where/why?
Maybe in C99, since the struct hack is undefined in C89?  Or
real life implementations, nothing to do with the standard?

That is,
   typedef <char or int> T;
   struct hack { Foo foo; T dynamic[1]; };
   struct hack h = malloc(sizeof *h) + sizeof(T)*n;
   .... use h->dynamic[0..n-1] ...;
would be safer with T = char than with T = int.

The C FAQ does not mention it.  And I know about C99
flexible array members, but that's not the question.

-- 
Hallvard

Back to comp.lang.c | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

"struct hack" with non-character array[1] Hallvard B Furuseth <h.b.furuseth@usit.uio.no> - 2011-08-19 12:28 +0200
  Re: "struct hack" with non-character array[1] Ian Collins <ian-news@hotmail.com> - 2011-08-19 23:15 +1200
    Re: "struct hack" with non-character array[1] Hallvard B Furuseth <h.b.furuseth@usit.uio.no> - 2011-08-19 15:12 +0200
    Re: "struct hack" with non-character array[1] falk@rahul.net (Edward A. Falk) - 2011-08-19 16:41 +0000
  Re: "struct hack" with non-character array[1] Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-08-19 08:01 -0400
  Re: "struct hack" with non-character array[1] James Kuyper <jameskuyper@verizon.net> - 2011-08-19 08:40 -0400
  Re: "struct hack" with non-character array[1] Keith Thompson <kst-u@mib.org> - 2011-08-19 09:41 -0700

csiph-web