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From: mrm@datagen.UUCP
Newsgroups: net.lang.c
Subject: Re: forward declared structures
Message-ID: <77@datagen.UUCP>
Date: Sat, 4-Aug-84 09:08:34 EDT
Article-I.D.: datagen.77
Posted: Sat Aug  4 09:08:34 1984
Date-Received: Wed, 8-Aug-84 19:12:32 EDT
Organization: Data General Distributed Systems, Westborough, MA
Lines: 21

The current ANSI draft does allow forward declaration of the pointer of
structures, since that is the only way you can build tree and list
structures with different typed structures.  Even in pascal, which is
much stricter about things, had to allow the forward declaration of pointers.

However, I believe that when the structure is declared, it must be in the same
block as the forward declaration.  Also, this forward declaration requires
that all structure/union pointers have the same format (or at least occupy
the same amount of storage) -- this means on a word-addressing machine (like
the DG stuff, DEC-20, UNIVAC, etc.) an implementator cannot make a pointer
to a structure which only contains chars be a byte pointer.

With regard to ANSI committees requiring large IBM-ish staffs to produce an
ANSI compiler, I beleive that most of us are on rather small teams.  I
ceratainly wouldn't agree to anythi
certainly wouldn't agree to anything that required a massive staff (since I
only have myself and an employee supporting two compilers).

	Michael Meissner
	Data General Corporation
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