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From: neath@solar-1.stars.flab.Fujitsu.JUNET
Newsgroups: comp.lang.c++
Subject: Pointers/References to Member Functions
Message-ID: <NEATH.89May3124020@solar-1.stars.flab.Fujitsu.JUNET>
Date: 3 May 89 03:40:20 GMT
Sender: news@ti-csl.csc.ti.com
Distribution: comp.lang.c++
Organization: Texas Instruments Data Systems Group, Austin TX
Lines: 33

A recent posting to this group discussed  the use of  typedef to specify a type
that is a `pointer to a member function  of class  X'. Can  this be extended to
include  a reference to  a member function? If not,  why not? Specifically, the
following code fragment results in a "internal <<cfront 1.2.1  2/16/87>> error:
bus error" message:

	class A {
	  int a;
	public:
	  A(int n) {a = n;};
	  void print() {cout << a;};
	};
	typedef void A::MEMF;
	MEMF* p1 = A:print;                // This is accepted by cfront
	MEMF& p2 = *A:print;               // This results in bus error!

What I am really trying to do is see  if there is a  mechanism that can be used
to implement  features similar to BEFORE,  AFTER, and   AROUND methods found in
Lisp.  If I can get access  to the pointer maintaining  the link to  the member
function of a class, I can change this  to point  to some function implementing
the  appropriate method behavior. This  functionality greatly  facilitates code
reuse, since it becomes much easier to take an existing class and make a slight
modification to it without having to derive a new class from it. Any comments?

Regards
Martin Neath <neath@dsg.ti.com>
------------------------------------------------------------------------
 DISCLAIMER: As always, the opinions expressed above are strictly my own
 and do not reflect those of my employer, Texas Instruments.
------------------------------------------------------------------------
--
Regards,
Martin