Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!ukma!psuvax1!swatsun!gessel
From: gessel@cs.swarthmore.edu (Daniel Mark Gessel)
Newsgroups: comp.lang.c++
Subject: Overloading typecast
Summary: Can one overload typecasting of pointers.
Keywords: overloading operators typecasting
Message-ID: <X5T4B5G@cs.swarthmore.edu>
Date: 25 Jun 91 14:08:45 GMT
Organization: Swarthmore College, PA, USA
Lines: 23

I have seen:
class X {
  public: 
    overload char *()
}
meaning overload the (char *) operator so that (char *)X can be meaningful.

I would like to overload the casting of a pointer to another pointer, in
user defined classes. I'm doing memory management and need to cast a pointer to
an abstract class object to a non-abstract subclass. If I can get control
of the casting operator, I can check a flag in the object itself.

Anybody know if it's available in C++ 2.0? (in particular Borland C++)
I saw it in an old C++ book. G++ seems to support it for the (char *) example
above, I just can't figure how to get it to typecast for pointers).

Any help much appreciated,

Dan

-- 
Daniel Mark Gessel
Internet: gessel@cs.swarthmore.edu