Path: utzoo!utgpu!water!watmath!clyde!rutgers!husc6!hao!oddjob!gargoyle!ihnp4!cbosgd!osu-cis!tut!lvc
From: lvc@tut.cis.ohio-state.edu (Lawrence V. Cipriani)
Newsgroups: comp.lang.c
Subject: Re: struct a <---> struct b
Message-ID: <6573@tut.cis.ohio-state.edu>
Date: 14 Feb 88 18:52:55 GMT
References: <11774@brl-adm.ARPA>
Organization: The Ohio State University Dept of Computer and Information Science
Lines: 45

In article <11774@brl-adm.ARPA> Alan_T._Cote.OsbuSouth@Xerox.COM writes:
>Finally -- one I can answer!!
>
>>What is the best way to declare three different structures, each containing a pointer
>>to the other two? I keep running into a forward referencing error.
>
>Try declaring all three as externals ahead of time.  Try the following:

The way I took this question was that the different structures are also of
different type.  If this is the case the answer is different.  Do the
following:

	struct a;	/* Hey compiler! a b and c are structures */
	struct b;	/* that I will define later */
	struct c;

	struct a
	{
		struct b *pb;
		struct c *pc;
		...	/* other stuff */
	};

	struct b
	{
		struct a *pa;
		struct c *pc;
		...	/* other stuff */
	};

	struct c
	{
		struct b *pb;
		struct c *pc;
		...	/* other stuff */
	};

The initialization of the pointers is left as an exercise for the
interested reader.

-- 
oo
Larry Cipriani, AT&T Networks Systems (by day) Ohio State University (by night)
Domain: lvc@tut.cis.ohio-state.edu
Path: ...!cbosgd!osu-cis!tut.cis.ohio-state.edu!lvc (yes its right)