Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!uwm.edu!lll-winken!elroy.jpl.nasa.gov!ben!richard
From: richard@ben.Jpl.Nasa.Gov (Conan the Barbarian)
Newsgroups: comp.lang.c++
Subject: pointer to function in varargs arguments
Keywords: pointer function varargs
Message-ID: <1990Mar19.190923.12448@elroy.jpl.nasa.gov>
Date: 19 Mar 90 19:09:23 GMT
Sender: news@elroy.jpl.nasa.gov (Usenet)
Distribution: usa
Organization: Image Analysis Systems Grp, JPL
Lines: 35

I am running into a strange problem trying to insert a
pointer to a member function in the argument list to 
a non-member function  while running the constructor on an instance
of a class. In short the translator gets lost and
puts garbage in the call. 

Sun c++ states that you should use &a::proc for the address
of member function proc in class a. This does give the 
correct value in the debugger but it can not be used in an
argument list.  I tried moving the address to a temporary pointer.  
For example if 
	void proc(char*);

is the declartation in a, then

	void (a::*func_ptr)(char*) = &a::proc;

should create a pointer to proc which I can insert in the
function call

	proc2(func_ptr);

(proc2 is not a member function of a.) 
The translator returns no errors with the use of the temporary.

However, func_ptr is not what it seems. It is not a pointer to
proc. It is a "structure" with member f pointing to proc. Except
that you may not reference member f. 

Anybody have any ideas on how to insert the pointer to a member
function in a non-member function call inside a constructor for a class?

(This is used to register a notifier function in xview. I know
c++ and xview don't mix.)