Newsgroups: comp.std.c++
Path: utzoo!utgpu!cunews!csi.uottawa.ca!news
From: hitz@csi.uottawa.ca (Martin Hitz)
Subject: Overloading Resolution
Message-ID: <1991Jun26.140508.19662@csi.uottawa.ca>
Summary: Standardization *IS* necessary
Keywords: Overloading Resolution, Argument Matching, Compiler Bugs
Sender: news@csi.uottawa.ca
Nntp-Posting-Host: sim5
Organization: University of Ottawa
Date: Wed, 26 Jun 91 14:05:08 GMT

In the course of testing my understanding of the rules for argument matching
given in section 13.2 in the ARM, I tried to predict the outcome of the
program given below. In order to verify my conclusions, I tried the
program with 4 different compilers (GNU g++, Sun's cfront, Zortech, and
Borland C++). As the results have been somewhat arbitrary, I'd like to
get your comments on who's right:

#include <stream.h>

void f (const double &, double, void *)		{ cout << 1; }
void f (double &, int, const char * = 0)	{ cout << 2; }
void f (int) 					{ cout << 3; }
void f (long, int = 0) 				{ cout << 4; }

main ()
{
	double b;
	const double pi = 3.14;
	
     			//	Z	g++	cfront	BC++
     			//---------------------------------------
	f(1.1, 1, f); 	//	1	err	err	1
	f(1, 1, "Y");	//	err	err	err	2
	f(3, 1.1, 0); 	// 	err	err	1	err
	f(1.1, 3, (void*)0);//	err	1	1	err
	f(1, 1);	// 	err	4	4	4
	f(pi, pi, "Y");	//	1	1	1	err
	f(0L); 		// 	4	3	4	4
	f(0L, 'a');	//	err	4	4	4
	f(pi);		//	err	3	err	err
}

Thanks, Martin Hitz@csi.uottawa.ca