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From: xor@aix01.aix.rpi.edu (Joseph Schwartz)
Newsgroups: comp.std.c
Subject: Pointers to Incomplete Types in Prototypes
Message-ID: <w!2g7+c@rpi.edu>
Date: 1 May 91 18:16:15 GMT
Organization: Rensselaer Polytechnic Institute, Troy NY
Lines: 24
Nntp-Posting-Host: aix01srv.aix.rpi.edu

Must an ANSI C compiler accept pointers to incomplete types in a
function prototype?
 
More specifically, if struct bar has not been defined, is an ANSI
compiler allowed to reject the following prototype:
 
    extern void foo(struct bar *);

According to 3.1.2.5, struct bar is an incomplete type in this case,
and struct bar * is a pointer to an incomplete type.
 
I couldn't find anything in 3.5.4.3 that allows or forbids incomplete
types, or pointers to them, in function prototypes.  Can anyone give
me more conclusive information?  Our HP "ANSI" C compiler is complaining
about the above prototype, and I want some ammunition before I report
it to HP as a problem.
 
Thanks in advance for any help you can provide.


-- 
Joe Schwartz
Internet: xor@mts.rpi.edu
Bitnet: userez3n@rpitsmts