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From: draves@harvard.UUCP (Richard Draves)
Newsgroups: net.lang.c
Subject: Re:  structure references in header files
Message-ID: <550@harvard.UUCP>
Date: Thu, 12-Dec-85 12:27:36 EST
Article-I.D.: harvard.550
Posted: Thu Dec 12 12:27:36 1985
Date-Received: Sat, 14-Dec-85 07:54:46 EST
References: <547@brl-tgr.ARPA> <2528@umcp-cs.UUCP>
Reply-To: draves@harvard.UUCP (Richard draves)
Organization: Aiken Comp Lab, Harvard
Lines: 25

In general it is important to include the 'forward declaration':

	struct a;
	struct b { struct a *pa; };
	struct a { struct b *pb; };

This makes a difference when the declarations are inside a scope
that already can see a definition of 'struct a'.  For instance,

	struct a { ... };
	main()
	{
		struct b { struct a *pa; };
		struct a { struct b *pb; };
		...
	}

does not do what one might expect.

Rich
-- 

	"a picture in the head is a gory murder in an art gallery"

					-- Stephen Kosslyn