Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!att!dptg!pegasus!hansen
From: hansen@pegasus.ATT.COM (Tony L. Hansen)
Newsgroups: comp.lang.c++
Subject: Re: Request for C++ coding "guidelines"
Summary: can't have multiple definitions of member functions
Keywords: C++, inlines, outlined member functions
Message-ID: <4481@pegasus.ATT.COM>
Date: 22 Feb 90 18:34:45 GMT
References: <2754@arran.tcom.stc.co.uk> <25D0B18E.27508@paris.ics.uci.edu> <4446@pegasus.ATT.COM> <25D3D824.15436@paris.ics.uci.edu>
Reply-To: hansen@pegasus.ATT.COM (Tony L. Hansen)
Organization: AT&T Bell Labs Middletown/Lincroft NJ USA
Lines: 31

In article <25D3D824.15436@paris.ics.uci.edu> rfg@ics.uci.edu (Ronald Guilmette) writes:
<In article <4446@pegasus.ATT.COM> hansen@pegasus.ATT.COM (Tony L. Hansen) writes:
<< I think that the comments lately have been pointing out problems with
<< some current implementations of inline functions:
<<	When the inline must be outlined, a static version will be
<<	created as needed in EVERY .o file where it is needed. When the
<<	.o's are combined, you suddenly have N occurrences of the
<<	static function which wastes considerable space.
<
< I believe that there are two serious problems with your scheme. First,
< some programmers out there have yet to "get religion" when it comes to
< avoiding the use of the preprocessor to do evil things.  Thus, you might
< see the following code in a C++ header file someday:
<
<	INLINE void foobar ()
<	{
<		some_var = SOME_MACRO;
<	}

The cfront 2.0 Reference Manual states (section 3.3)

	"There must be exactly one definition for each function, object, and
	class in a program."

In an environment such as cfront and g++ provide, this is almost impossible
to detect or enforce. In other environments, it may be easy to detect and
enforce.

					Tony Hansen
				att!pegasus!hansen, attmail!tony
				    hansen@pegasus.att.com