Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!uc!nic.MR.NET!hal!ncoast!allbery
From: allbery@NCoast.ORG (Brandon S. Allbery)
Newsgroups: comp.lang.c
Subject: Re: A solution to the multiple inclusion problem
Message-ID: <1989Oct25.235432.4261@NCoast.ORG>
Date: 25 Oct 89 23:54:32 GMT
References: <14240@well.UUCP> <1989Oct23.191634.6345@cs.rochester.edu> <1659@atanasoff.cs.iastate.edu> <14790@bfmny0.UU.NET>
Reply-To: allbery@ncoast.ORG (Brandon S. Allbery)
Followup-To: comp.lang.c
Distribution: comp
Organization: North Coast Public Access UN*X, Cleveland, OH
Lines: 25

As quoted from <14790@bfmny0.UU.NET> by tneff@bfmny0.UU.NET (Tom Neff):
+---------------
| In article <1659@atanasoff.cs.iastate.edu> hascall@atanasoff.UUCP (John Hascall) writes:
| >    Since the impending ANSI standard requires that including a file more
| >    than once have exactly the same effect as including it once...why can't
| >    a compiler just ignore #includes for files it has already #included???
| 
| Including standard HEADER files should be idempotent.  Back here in the
| real world there are plenty of uses for including a file multiple times
| with a desired substantial effect on each inclusion.  Examples include
+---------------

Agreed.  I have simulated packages this way, e.g.

	#define PACKAGE_NAME foo
	#define PACKAGE_TYPE float
	#include "package.h"

++Brandon
-- 
Brandon S. Allbery:  allbery@NCoast.ORG, BALLBERY (MCI Mail), ALLBERY (Delphi)
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>>>	 Shall we try for comp.protocols.tcp-ip.eniac next, Richard?	    <<<