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From: sho@maxwell.physics.purdue.edu (Sho Kuwamoto)
Newsgroups: comp.lang.c++
Subject: pointers to methods
Message-ID: <3063@pur-phy>
Date: 5 Feb 90 07:18:35 GMT
Sender: news@pur-phy
Reply-To: sho@maxwell.physics.purdue.edu.UUCP (Sho Kuwamoto)
Organization: Purdue Univ. Physics Dept., W. Lafayette, IN
Lines: 41

I'm not up on 2.0 (did Stroustrup come out with a book yet?  I haven't
been paying much attention to this group lately) but is there any
standard way you can get a pointer to a member function?  How does it
work?  I want something like this:

  funcPtr = className::func;
  instance->funcPtr(arg1, arg2);

Not possible?  Ach so.  What about:

  funcPtr = instance->func;
  funcPtr(arg1, arg2);

Although this version seems harder to implement and uglier to boot.

Now for the big finale.  I'd like something like this, but one which works
for virtual functions.

  class old {                  |       class new : public old {
  public:		       |       public:                 
    virtual void fester();     |         void fester();        
  };			       |       };                      

  funcPtr = old::fester;
  oldThing->funcPtr();
  newThing->funcPtr();

TaDaa!  Another pipe dream.  This would give me more faith that C++
was an object oriented programming language, with messages being
passed around, so forth.  As it is now, I can't shake the feeling that
it's just a big program that mangles names for you.  The only thing
that differentiates C++ from such a mangler program (in my mind) is
virutal functions.  If something like the above is possible (which it
might be), you'd also have containers to put messages in, which you
could then send to different types of objects.

-Sho
--
sho@physics.purdue.edu  <<-- now, all we need is a type variable.  and
                             standard support for generics (or maybe
                             some other more elegant meta-class thing)