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From: sakkinen@tukki.jyu.fi (Markku Sakkinen)
Newsgroups: comp.object
Subject: Re: The Emperor Strikes Back
Message-ID: <1991Mar8.061042.5578@tukki.jyu.fi>
Date: 8 Mar 91 06:10:42 GMT
References: <PCG.91Feb28214244@odin.cs.aber.ac.uk> <1991Mar5.225458.4408@m.cs.uiuc.edu> <PCG.91Mar6194500@aberdb.cs.aber.ac.uk>
Reply-To: sakkinen@jytko.jyu.fi (Markku Sakkinen)
Organization: University of Jyvaskyla, Finland
Lines: 56

In article <PCG.91Mar6194500@aberdb.cs.aber.ac.uk> pcg@cs.aber.ac.uk (Piercarlo Antonio Grandi) writes:
>On 5 Mar 91 22:54:58 GMT, johnson@cs.uiuc.EDU (Ralph Johnson) said:
>
>johnson> It appears that Piercarlo and I use different terminology.  Perhaps
>johnson> this explains our inability to agree.
>
> [a lot deleted]
>
>I know abpout the output of cfront, and I can tell you that your
>impression of it is inaccurate.  [...]
> ...
>
>I will give another example, in C++:

It would help to make people believe that you really know much about C++
if your examples were approximately correct.

>Suppose we have the following:
>
>	struct Complex { float re, im; };
>
>[1]	Complex operator +(const Complex &a,&b)
>	{ return Complex(a.re+b.re,a.im+b.im; }

That one parenthesis is missing does not mislead anybody.
However, you must either declare a constructor in the obvious way
within the 'struct' declaration
or use braces in the 'return' statement to make a structure initialiser.
Let's suppose the former alternative, i.e.
    Complex (float x, y) {re = x; im = y;}

>compared with
>
>	struct Complex {
>	    float re,im;
>
>[2]	    Complex operator +(const Complex &b) const
>	    { return re+b.re,im+b.im};
>	};

The compiler would complaining that you are returning a float instead
of Complex.  That's the stupid sequencing operator of C and C++.
You must actually write:
    { return Complex (re+b.re, im+b.im); }
assuming the same constructor as above.
A similar correction is needed for example [3].

> [rest deleted]

Markku Sakkinen
Department of Computer Science and Information Systems
University of Jyvaskyla (a's with umlauts)
PL 35
SF-40351 Jyvaskyla (umlauts again)
Finland
          SAKKINEN@FINJYU.bitnet (alternative network address)