From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID
	autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: fac41,b87849933931bc93
X-Google-Attributes: gidfac41,public
X-Google-Thread: 109fba,b87849933931bc93
X-Google-Attributes: gid109fba,public
X-Google-Thread: 1108a1,b87849933931bc93
X-Google-Attributes: gid1108a1,public
X-Google-Thread: f43e6,b87849933931bc93
X-Google-Attributes: gidf43e6,public
X-Google-Thread: 103376,b87849933931bc93
X-Google-Attributes: gid103376,public
X-Google-Thread: 114809,b87849933931bc93
X-Google-Attributes: gid114809,public
From: ohk@ultra.tfdt-o.nta.no (Ole-Hjalmar Kristensen FOU.TD/DELAB)
Subject: Re: OO, C++, and something much better!
Date: 1997/01/06
Message-ID: <OHK.97Jan6132731@ultra.tfdt-o.nta.no>#1/1
X-Deja-AN: 208045521
references: <JSA.97Jan1181506@alexandria>
organization: Telenor Online Public Access
newsgroups: 
 comp.lang.c++,comp.lang.smalltalk,comp.lang.eiffel,comp.lang.ada,comp.object,comp.software-eng
Date: 1997-01-06T00:00:00+00:00
List-Id: <comp.lang.ada>


In article <32D0CA27.44C2@ghgcorp.com> Stanley Allen <sallen@ghgcorp.com> writes:


   John (Max) Skaller wrote:

   > Is C++ innovative? Too right it is.
   > It has the most powerful support for genericity available
   > in any widely used commercial language. (Sorry, Ada doesn't count,
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

   You loaded the question, and therefore your dismissal of
   Ada is the act of knocking down a strawman.

   Let me engage in some debuking here, and point out that Ada
   *is* widely used, just not in the PC/GUI world.  Ada is also
   very much a "commercial" language; in fact, many of the
   companies using Ada today for commercial projects consider
   it to be a success factor in their software efforts.

   To hear that C++'s template mechanism is "innovative" and
   "powerful" comes as a surprise.  Parts of the C++ template
   mechanism look like a borrowing of Ada's "generic" facility
   (Stroustrup attributes this to Alex Stepanov, who had done
   a great deal of work with Ada generics before designing the
   C++ Standard Template Library).  Unfortunately, the type
   system in C++ is too weak to support anything as powerful
   as Ada's generic facility.  The C++ "template argument"
   (which corresponds to Ada's "generic formal parameter") for
   a type can only be of the form "class T".  In Ada terms,
   this would be like having all generic formals be
   "type T is private".

<stuff deleted>


   --
   Stanley Allen
   mailto:sallen@hso.link.com


I would tend to agree. Another point is that C++ templates tend to be
implemented differently in every compiler, so a program which uses
templates heavily is often less portable.

However, if I remember correctly, Alex Stepanov had earlier tried to
implement a library like the C++ STL in Ada, but was incapable of
doing it. This would indicate that the C++ template mechanism is more
flexible than the Ada generics.
Any comments?