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From: ahodgson@athena.mit.edu (Antony Hodgson)
Newsgroups: comp.os.msdos.programmer
Subject: BC++ Precompiled Header Bug
Message-ID: <1991Mar22.170134.11852@athena.mit.edu>
Date: 22 Mar 91 17:01:34 GMT
Sender: news@athena.mit.edu (News system)
Organization: Massachusetts Institute of Technology
Lines: 29

I just reported the following bug involving precompiled headers to Borland.

File:  bar.h

	class foo { public:  foo() {} };
	class bar { public:  bar( foo = foo() ) {} };

File:  main.cpp

	#include <iostream.h>
	#include "bar.h"

	main()
	{
		bar b;
		cout << "Done.\n";
	}

If one builds this program with precompiled headers ON, then it runs fine.
If you then touch main.cpp and recompile, the .obj and .exe files have
a different size and the program crashes your system when you run it.
This happens in the IDE under any memory model and regardless of the 
state of the DEBUG INFO IN OBJ option.  Interestingly, if class foo
is eliminated and the bar constructor changed to bar( int = 1 ), all 
is fine.  Turning precompiled headers off solves the problem, but that
definitely defeats the purpose of precompilation.

Tony Hodgson
ahodgson@hstbme.mit.edu