Xref: utzoo comp.lang.c++:12800 comp.std.c++:818 comp.object:3113
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!uunet!mnemosyne.cs.du.edu!cag
From: cag@mnemosyne.cs.du.edu (Chris Gantz)
Newsgroups: comp.lang.c++,comp.std.c++,comp.object
Subject: C++ possible new construct proposal
Message-ID: <1991Apr11.155803.5410@mnemosyne.cs.du.edu>
Date: 11 Apr 91 15:58:03 GMT
Organization: University of Denver, Dept. of Math & Comp. Sci.
Lines: 72

Hello C++ netters,

I don't know if this subject has been address before on the net, but I have
been thinking about a possible C++ implementation of the following Object 
Oriented Programming Concept that may be useful for the development of large
systems.  The Concept is being able to utilize a "Type" as though it were an
object. This mechanism could be valuable because it would allow a logically 
clean way of managing type information.  That is, information that is relevant
only to types and not logically relevant to instances of a type. Below is an 
example that illustrates a simple declaration and use within the C++ framework.

        class X {
         type:
                private:
                     // internal data representation for type;
		     int no_instantiations;
                protected:
                     // protected interface for type;
                public:
		     int instantaitions() {
		        return instantiations;
		     }
		     void update_instantiations() {
			 no_instantitations++;
		     }
         object:
                private: 
                     // internal data representation for objects; 
                protected: 
                     // protected interface for objects;
                public: 
                    X() { // default constructor 
                          update_instantiations() 
			  // object appropriate internal data initialization.
		    } 
                   ~X() { } 
		    void f() { }
        };


	main()
	{
	    X x_obj;

	    x_obj.f(); // using x_obj through the object public interface
	    // below is an example of using the type X as an object...
	    no_current_instantiations = X.instantiations();
	    
	}


I believe that this language inclusion would integrate nicely with what
is already available and not add any new anomalies in the language..
Well I have on my asbestos suit on, so flame away people, but I do hope
that some people will consider the possible addition useful.

Chris Gantz                             
Dept. of Math & Computer Science  Internet:    cag@mnemosyne.cs.du.edu
RM 306, JGH                                    cgantz@diana.cair.du.edu
University of Denver                           cag@aragtap.den.mmc.com
Denver, CO 80208                     Voice:    (303) 871-3095

Martin Marietta Corp.             Internet:    cag@airob.mmc.com
M/S XL4370                                     cag@maxai.den.mmc.com
P.O. Box 1260.                                 cag@aragtap.den.mmc.com
Denver, CO 80201-1260                Voice:    (303) 971-3347 

-- 
Chris Gantz				Internet: cag@mnemosyne.cs.du.edu
Dept. of Math & Computer Science		  cgantz@diana.cair.du.edu
University of Denver				  cag@aragtap.den.mmc.com
Denver, CO 80208			Grad. Student