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: 103376,8f4d148bde72b77d,start X-Google-Attributes: gid103376,public From: Michael.P.Card@lmco.com Subject: True confessions RE:Multiple Inheritance Date: 1997/09/25 Message-ID: <875229433.29719@dejanews.com>#1/1 X-Deja-AN: 275539129 X-Http-User-Agent: Mozilla/3.01 (X11; U; SunOS 5.5 sun4m) X-Originating-IP-Addr: 192.91.146.35 (proxy3b.lmco.com) Organization: Deja News Posting Service X-Authenticated-Sender: Michael.P.Card@lmco.com X-Article-Creation-Date: Thu Sep 25 23:17:14 1997 GMT Newsgroups: comp.lang.ada Date: 1997-09-25T00:00:00+00:00 List-Id: I thought everyone might enjoy the following post which appeared on comp.lang.eiffel this evening: Ingo Pakleppa (ingop@cts.com) wrote RE: absence of MI in Java: >Where is the problem? A book is loanable - but being loanable is not an >intrinsic feature of the book, when you are talking about real-life >books (this may be different if you are developing a library check-out >application, where loanable is the primary information of interest). So >just derive BOOK from PUBLICATION, implement the LOANABLE interface, and >contains a LOANABLEOBJECT member. All you have to actually implement, >you just have to provide the member functions that forward all calls to >the embedded LOANABLEOBJECT. > >In my almost ten years of C++ programming, I have used multiple >inheritance maybe 10 times at the most, and 80% of that was for mix-in ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >classes such as making objects collectable - where interfaces are >actually better than MI. > >So - when I started Java, I thought I was going to miss MI, but by now >find that I don't really need it in the first place. The reason I thought this worthy of mention is that I have seen Ada bashed for not suppporting MI. The use of generics/tagged types for mixin inheritance has been described as a poor substitute for "the real thing", and the advocates for some other languages often crow about their support of "true MI." I have also seen many posts comp- laining about the complexity of using "true MI" on the newsgroups of these languages, however. We have done a lot of work here with Ada 95 and I believe we are really pushing the limits of the language as we attempt to build a real-time object database management engine in Ada. I have been continually impressed by the work done by the Ada 95 team. On our program, we do not have a need for "true MI", so the fact that Ada doesn't have it has never bothered us. Posts like the one I quoted here lead me to believe that the Ada 95 team did the right thing when they omitted it. - Mike --------------- Michael P. Card Lockheed Martin Ocean, Radar and Sensor Systems Division Syracuse, NY 13221 voice: (315)-456-3022 FAX: (315)-456-2414 e-mail:card@syr.lmco.com -------------------==== Posted via Deja News ====----------------------- http://www.dejanews.com/ Search, Read, Post to Usenet