Path: utzoo!utgpu!water!watmath!watdragon!violet!gjditchfield
From: gjditchfield@violet.waterloo.edu (Glen Ditchfield)
Newsgroups: comp.lang.c++
Subject: Re: possible bugs
Summary: New version of pointer-to-function parameter bug.
Keywords: pointer-to-function parameters
Message-ID: <6170@watdragon.waterloo.edu>
Date: 1 Apr 88 19:16:39 GMT
References: <6112@watdragon.waterloo.edu> <552@cord.UUCP>
Sender: daemon@watdragon.waterloo.edu
Reply-To: gjditchfield@violet.waterloo.edu (Glen Ditchfield)
Distribution: na
Organization: U. of Waterloo, Ontario
Lines: 36

In article <552@cord.UUCP> gwr@cord.UUCP (59451-GW Ryan) writes:
>In article <6112@watdragon.waterloo.edu> gjditchfield@violet.UUCP writes:
>>	typedef int (*PFCCI)(char, char); // ptr to fn mapping 2 chars to int.
>>	void g( int (*p)(char, char) );
>i don't understand what you are trying to do here. g() is supposed to be
>a function taking what parameters?

I want g() to have one parameter, and I want that parameter to be a pointer
to a function that takes two characters and returns an integer.  The body
of g() will call that parameter with characters of its own choosing.
Imagine passing an ordering routine down to a sort function.

Here's a more interesting version of the problem, again using Cfront 1.2.1.
	----------------------------------------
	int f( char* s, int (*p)(char, char) ) {
	    return 0;
	    };
	
	int g( int (*p)(char, char) ) {
	    return 0;
	    };
	----------------------------------------
	ccc  pmf2.cc:
	"pmf2.cc", line 3: warning:  s not used
	"pmf2.cc", line 3: warning:  p not used
	"pmf2.cc", line 5: error: syntax error
	"pmf2.cc", line 5: error: syntax error
	"pmf2.cc", line 5: error: syntax error
	"pmf2.cc", line 5: error: syntax error
	"pmf2.cc", line 6: error: syntax error
	"pmf2.cc", line 6: error: syntax error
	"pmf2.cc", line 7: error: syntax error
	7 errors
	----------------------------------------
One declaration of p is accepted, but the other is illegal.  Is g()
accepted by later versions of cfront?