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From: bernt@wolfen.cc.uow.oz (Bernt Ribbum)
Newsgroups: comp.lang.c++
Subject: Pointers to functions anyone?
Summary: How do I do this???
Keywords: pointer-to-functions inside class
Message-ID: <6472@wolfen.cc.uow.oz>
Date: 24 Sep 90 13:21:45 GMT
Distribution: comp
Organization: Uni of Wollongong, NSW, Australia
Lines: 43


Hello Networld!

Anyone who could help a newcomer to C++?
I'm trying to set up an array of pointers to functions within a class,
much like the example here (for simplicity no array here):

#include <stream.h>

class test {
  void f1(int i)			// function to be called
    { cout<<"ok"<<i<<"\n"; }

  void (test::*ptf)(int);		// pointer-to-function

B
public:
  test() { ptf=test::f1; }		// constructor - assigns &f1 to ptf
  void execute (int i)
    { (*ptf)(i); }			// try to call f1()
};

main() {
  test variable;
  variable.execute(1);
}

My compiler (Turbo C++ V1.0) complains about the call (*ptf)(i):

-- Temporary used for parameter 'this' in function test::execute(int)
-- Type mismatch in parameter 'this' in function test::execute(int)
-- Parameter 'i' is never used in function test::execute(int)

What am I doing wrong?? It is a perfectly legal setup outside of classes
in any case! Or maybe I should use another way to do this?

Please email replies - I'll summarise here if someone has a solution!
Thanks,
-- 
  _
 /_) _  _  _  _/  Bernt Ribbum, Dept of Elec & Comp Eng, Univ of Wollongong
/_) (-'/ '/ > (   PO.Box 1144, Wollongong NSW 2500, AUSTRALIA  ------------
----------------  bernt@wolfen.cc.uow.edu.au  -----------------------------