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=0.2 required=5.0 tests=BAYES_00,INVALID_MSGID, REPLYTO_WITHOUT_TO_CC 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: 114809,b87849933931bc93 X-Google-Attributes: gid114809,public X-Google-Thread: 1108a1,b87849933931bc93 X-Google-Attributes: gid1108a1,public X-Google-Thread: 103376,b87849933931bc93 X-Google-Attributes: gid103376,public X-Google-Thread: f43e6,b87849933931bc93 X-Google-Attributes: gidf43e6,public From: donh@syd.csa.com.au (Don Harrison) Subject: Re: OO, C++, and something much better! Date: 1997/01/17 Message-ID: #1/1 X-Deja-AN: 210336125 sender: news@syd.csa.com.au x-nntp-posting-host: dev50 references: organization: CSC Australia, Sydney reply-to: donh@syd.csa.com.au newsgroups: comp.lang.c++,comp.lang.smalltalk,comp.lang.eiffel,comp.lang.ada,comp.object,comp.software-eng Date: 1997-01-17T00:00:00+00:00 List-Id: Jon S Anthony writes: :Where's the polymorphism of :any form here? Subtypes are ways of defining constraints (simple :"assertions") on the possible values of the type. Sub_Integer is not :a new type and is not a type derivation. So, you only have one type :here (Re: RM: 3.2(8)) : :The CE, is simply stating that you have violated the constraint :(assertion). No polymorphism broken or otherwise involved. Yes, if you define subtypes as such, then I concede it may be more reasonable to regard this as simply an assertion violation and declare the type system free of holes. It's a question of definition. :Also, while it is certainly not necessary, this case is so simple (for :DFA) I am a little surprised that GNAT did not give a warning about :this at compile time. I compiled it with the Sun Ada 1.1(f) Ada83 compiler. I agree it ought to give a warning. Don. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Don Harrison donh@syd.csa.com.au