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From: mjv@objects.mv.com (Michael J. Vilot)
Newsgroups: comp.lang.c++
Subject: RE: Generics in C++
Message-ID: <1274@zinn.MV.COM>
Date: 10 Apr 91 11:43:12 GMT
Sender: news@ditka.chicago.com (Pulitzer at ditka)
Lines: 38

>From cs.wvu.wvnet.edu!schiebel
>Newsgroups: comp.lang.c++
>Keywords: generic
>Message-ID: <1410@h.cs.wvu.wvnet.edu>
>
>We are designing a reuseable software library based on C++ 
components.
>Currently we are exploring the various (twisted) ways of 
implementing
>a "generics" layer on C++. The alternatives seem to be:
>
>	1) Pointer Based Objects on top of C++ (Smalltalkish)
>	2) Pre-processor based macro generics with type substitution and
>		using the "generic header file."
>	3) A yacc/sed/awk preprocessor for implimenting the generics
>		((C++)++) 
>
>Does anyone have a better solution? 

I faced exactly this problem when designing the C++ Booch Components 
library.  I decided on:
  4)  A template filter program (written in C++) that implements the 
(essential parts of) template processing described in Chapter 14 of 
"The Annotated Reference Manual."

The filter sits between cpp and the C++ compiler.  This approach let 
me build the library using the syntax that will eventually be 
supported in all C++ implementations, and make the library available 
on any platform supporting C++.

For more details, you might want to read the paper Grady and I 
presented:
  "The Design of the C++ Booch Components,"  OOPSLA/ECOOP Conference, 
Ottawa Canada, October 1990, p. 1.

Hope this helps,

Mike