Path: utzoo!utgpu!water!watmath!clyde!rutgers!ames!sdcsvax!sdcc6!ix426
From: ix426@sdcc6.ucsd.EDU (tom stockfish)
Newsgroups: comp.lang.c
Subject: Re: Power operator?
Message-ID: <3572@sdcc6.ucsd.EDU>
Date: 11 Jan 88 00:44:12 GMT
References: <47000029@uxe.cso.uiuc.edu> <5260001@hplsla.HP.COM>
Reply-To: ix426@sdcc6.ucsd.edu.UUCP (tom stockfish)
Organization: University of California, San Diego
Lines: 28

In article <5260001@hplsla.HP.COM> jima@hplsla.HP.COM (              Jim Adcock) writes:
>Don't use ANSI-C, use C++, and overload the -> operator.
>Then you can write: twoToTheTenth = 2.0->10.0;

So when will C++ be available on enough machines that we numerical users
can write in it and be assured of support when we change employers/machines?

The C code that is emitted by CC is *not* portable, chiefly because things
like getchar() are already expanded into their machine-specific inline code.
Even if this problem could be gotten around, I would hate to have to maintain
that C code.

I like your choice for the operator.  It seems to me this would work nicely
if ANSI-C adopted it.  It will *not* work for the example you give (2.0->10.0)
because at least one operand of an overloaded operator must be a class object.
(See Stroustrup's book p. 172).
Supplying a trivial floating point class and supplying identity-operation
constructors for it should do the trick, but you still won't be able to do

	constant -> constant

without using a cast.  If I'm wrong about this, or C++ has been extended to
allow overloading of operators on basic types when the basic types don't
have a normal meaning with an operator, I would like to hear about it.

-- 

||  Tom Stockfisch, UCSD Chemistry   tps@chem.ucsd.edu