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,XPRIO autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,ee0a468e6667bd1,start X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-12-18 10:27:21 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news.uchicago.edu!newsswitch.lcs.mit.edu!newsfeed.mathworks.com!wn3feed!worldnet.att.net!204.127.198.203!attbi_feed3!attbi.com!rwcrnsc53.POSTED!not-for-mail From: "Mark Lundquist" Newsgroups: comp.lang.ada Subject: Ada95 language design question (accessibility rules and type extensions) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 Message-ID: NNTP-Posting-Host: 9ULT7-31333-NM4-97669@rwcrnsc53 X-Complaints-To: abuse@attbi.com X-Trace: rwcrnsc53 1008700041 9ULT7-31333-NM4-97669@rwcrnsc53 (Tue, 18 Dec 2001 18:27:21 GMT) NNTP-Posting-Date: Tue, 18 Dec 2001 18:27:21 GMT Organization: AT&T Broadband Date: Tue, 18 Dec 2001 18:27:21 GMT Xref: archiver1.google.com comp.lang.ada:18062 Date: 2001-12-18T18:27:21+00:00 List-Id: The invocation of accessibility rules in RM 3.9.1(3) is designed to prevent dangling dispatch. It seems to me that another way would have been to disallow assignment of a tagged type to the classwide type of a statically shallower parent. Does anyone know why that would not have worked? What got me started thinking on this was the common complaint about the implementation of controlledness, and the ramification of this rule that controlled types can't be declared deeper than library-level... -- mark -------------- Reply by email to: Mark dot Lundquist at ACM dot org Consulting services: http://home.attbi.com/~mlundquist2/consulting