Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!spool.mu.edu!uunet!pilchuck!dataio!fnx!nazgul!bright
From: bright@nazgul.UUCP (Walter Bright)
Newsgroups: comp.lang.c++
Subject: Re: C < X < C++,  worthwhile(X), solve for X
Keywords: implementation, object oriented, sanity
Message-ID: <331@nazgul.UUCP>
Date: 25 May 91 17:25:29 GMT
Article-I.D.: nazgul.331
References: <1991May23.115050.5755@dit.upm.es>
Reply-To: bright@nazgul.UUCP (Walter Bright)
Organization: Zortech, Seattle
Lines: 20

In article <1991May23.115050.5755@dit.upm.es> esink@turia.dit.upm.es (Eric W. Sink) writes:
/Several months ago, I posting a question to the net, asking
/how difficult it would be to modify a C compiler into a C++ compiler.
/   Hard.  Really hard.  Most people don't realize just how difficult
/   is to parse C++.  Any quantitative estimate of the effort would
/   no doubt be ruinously low.  All known attempts at making a C++ compiler
/   out of a C compiler have failed.

Not true. Zortech C++ grew out of Zortech C. In fact, the sources for the
two parsers are the same, with #ifdef's for the differences. It turns out
that the C++ stuff nearly doubles the size of the parser.

C++ is like an iceberg, the visible part looks nice and pretty. What goes
on under the surface is pretty hairy and dangerous, and have sunk more
than one attempt to implement it.

Myself, (and some others!), thought that implementing a C++ compiler was
just adding a few keywords, and about 3 months of twiddling. Ha!
If you want a time estimate, try 2 to 3 years given an existing ANSI C
compiler.