Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!mcvax!kth!draken!tut!tukki!sakkinen
From: sakkinen@tukki.jyu.fi (Markku Sakkinen)
Newsgroups: comp.lang.c++
Subject: Re: Arguments to Overloaded Operators
Keywords: overloading
Message-ID: <884@tukki.jyu.fi>
Date: 13 Jun 89 09:05:22 GMT
References: <11032@orstcs.CS.ORST.EDU> <1100@cadillac.CAD.MCC.COM> <238@pink.ACA.MCC.COM> <868@tukki.jyu.fi> <244@pink.ACA.MCC.COM> <5023@wiley.UUCP>
Reply-To: markku@jytko.jyu.fi (Markku Sakkinen)
          SAKKINEN@FINJYU.bitnet (alternative)
Organization: University of Jyvaskyla, Finland
Lines: 42

In article <5023@wiley.UUCP> simpson@poseidon.UUCP (Scott Simpson) writes:
-In article <244@pink.ACA.MCC.COM> rfg@pink.aca.mcc.com.UUCP (Ron Guilmette) writes:
->In article <868@tukki.jyu.fi> markku@jytko.jyu.fi (Markku Sakkinen) SAKKINEN@FINJYU.bitnet (alternative) writes:
->>In article <238@pink.ACA.MCC.COM> rfg@pink.aca.mcc.com.UUCP (Ron Guilmette) writes:
->>One example of these
->>is the widening of char values to int in many contexts: it even prevents us
->>from declaring an overloaded function pair corresponding to the _argument_
->>types char and int.
->
->Who sez?  I believe this is legal now.
-
-Indeed it is.  See section 8.4.1, page 236 in Stroustrup.  There are
-a few lines like
-	
-	istream& operator>>(char&);
-	istream& operator>>(short&);
-	istream& operator>>(int&);
-	Scott Simpson
-	TRW Space and Defense Sector
-	oberon!trwarcadia!simpson  	(UUCP)
-	trwarcadia!simpson@usc.edu	(Internet)

This just came here when I had posted my previous (long) article.
The trick is that this example has _reference_ arguments,
which are almost the same as pointers.
A pointer to char is definitely distinct from a pointer to int;
this is clearly necessary for pointer arithmetic.

If you look at subsection 8.2.1 (page 227) of Stroustrup,
you can see (among others) the output operator and function
	ostream& operator<<(int) { ... }
	ostream& put(char&);
Guess why there isn't
	ostream& operator<<(char);
instead of the put function!

Markku Sakkinen
Department of Computer Science
University of Jyvaskyla (a's with umlauts)
Seminaarinkatu 15
SF-40100 Jyvaskyla (umlauts again)
Finland