Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!microsoft!jimad
From: jimad@microsoft.UUCP (Jim ADCOCK)
Newsgroups: comp.lang.c++
Subject: Re: friend operator +(l,r) vs. operator +(r)
Message-ID: <59437@microsoft.UUCP>
Date: 30 Nov 90 00:12:21 GMT
References: <11759@hubcap.clemson.edu> <1990Nov21.053431.22340@actrix.co.nz>
Reply-To: jimad@microsoft.UUCP (Jim ADCOCK)
Organization: Microsoft Corp., Redmond WA
Lines: 16

Koenig has a good discussion of this and other frequent C++ questions
in November's JOOP.  He points out that symmetric operators should _be_
symmetric.  Using members:

	l + r;

is equivalent to 

	l.operator+(r);

which clarifies the assymmetry.  Using friends instead this becomes:

	operator+(l, r);

maintaining symmetry [both l and r are parameters treated similarly.]
Conversely, non-symmetric operators need not be friends.