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From: mark@umcp-cs.UUCP (Mark Weiser)
Newsgroups: net.lang.st80,net.lang.c++
Subject: Re: Xerox Star "traits"
Message-ID: <185@umcp-cs.UUCP>
Date: Mon, 10-Mar-86 22:43:54 EST
Article-I.D.: umcp-cs.185
Posted: Mon Mar 10 22:43:54 1986
Date-Received: Wed, 12-Mar-86 22:52:12 EST
References: <296@bambi.UUCP>
Reply-To: mark@maryland.UUCP (Mark Weiser)
Distribution: net
Organization: U of Maryland, Computer Science Dept., College Park, MD
Lines: 20
Xref: watmath net.lang.st80:326 net.lang.c++:75

In article <296@bambi.UUCP> mike@bambi.UUCP writes:
>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've used Mesa (have an XDE machine next to me right now), but my reading
of the traits paper is that it was all done with mirrors, or more exactly,
managers.  The paper never comes out and says there was any preprocessor
to Mesa code at all, and if there was, why not say so?  So I think the traits
business was a discipline, programmer enforced, nothing more.  But I would
like to know for sure.
-mark
-- 
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