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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,4deb6c62a5e19f2 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-07-29 20:10:19 PST Path: archiver1.google.com!newsfeed.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!news.stealth.net!204.127.161.2.MISMATCH!wn2feed!worldnet.att.net!135.173.83.71!wnfilter1!worldnet-localpost!bgtnsc04-news.ops.worldnet.att.net.POSTED!not-for-mail Message-ID: <3B64D0B0.33323E3B@worldnet.att.net> From: James Rogers X-Mailer: Mozilla 4.76 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: type Foo_ptr in new void*; References: <9k03jc$2me$2@news.tpi.pl> <9k0j60$n4t$1@news.tpi.pl> <3B63F48A.2E2642C6@earthlink.net> <9k2btj$5hj$1@news.tpi.pl> <3B64C26F.C195B4E0@worldnet.att.net> <3B64C812.8CA53003@home.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Mon, 30 Jul 2001 03:10:18 GMT NNTP-Posting-Host: 12.86.33.111 X-Complaints-To: abuse@worldnet.att.net X-Trace: bgtnsc04-news.ops.worldnet.att.net 996462618 12.86.33.111 (Mon, 30 Jul 2001 03:10:18 GMT) NNTP-Posting-Date: Mon, 30 Jul 2001 03:10:18 GMT Organization: AT&T Worldnet Xref: archiver1.google.com comp.lang.ada:10710 Date: 2001-07-30T03:10:18+00:00 List-Id: "Warren W. Gay VE3WWG" wrote: > > I don't think your "unspecified behavior" assertion is truly fair here. > I believe that when you reach a point in the C/C++ compile where > pointer arithmetic is required on the "undefined type", you will get > a compile error. The compiler will not generate code that does > "undefined behaviour" here. If there is any further doubt about it, > I am sure this can be tested with a short example program. Your assertion may be true for C++ compilers, but it was not true for C compilers in the early 1990s. > Ada does permit you to define an incomplete type as well, but the > condition is that it must be defined eventually. I agree that enforcing > its later definition, is a good thing. Let's be a little more precise here. Ada does not allow you to define incomplete types. It allows you to define unconstrained types. There is a real difference. All Ada objects are fully defined. You cannot make an unconstrained instance of an unconstrained type. Jim Rogers Colorado Springs, Colorado USA