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From: mike@bambi.UUCP (Michael Caplinger)
Newsgroups: net.lang.st80,net.lang.c++
Subject: Xerox Star "traits"
Message-ID: <296@bambi.UUCP>
Date: Thu, 6-Mar-86 15:34:52 EST
Article-I.D.: bambi.296
Posted: Thu Mar  6 15:34:52 1986
Date-Received: Sat, 8-Mar-86 03:00:14 EST
Distribution: net
Organization: Bell Communications Research Inc., Morristown, NJ
Lines: 15
Xref: watmath net.lang.st80:321 net.lang.c++:61

Does someone know how the "traits" multiple-inheritance scheme was implemented
on the Xerox Star?  There are a couple of clues in the literature (see
for example the paper in the '82 Siggraph proceedings) but the exact
implementation details were "beyond the scope of this paper."  Other
papers mention something called a "traits manager", but don't say how it
works.

I'm interested in just how they were able to implement this scheme without
bypassing the type checking in Mesa -- particularly for "replaceable"
(read Simula/C++ "virtual") functions, and still not do any lookup/
type resolution at runtime.

	Mike Caplinger
	mike@bellcore.arpa
	ihnp4!bambi!mike