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-Thread: 103376,f428ff2031155951 X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII Path: g2news1.google.com!postnews.google.com!y19g2000prb.googlegroups.com!not-for-mail From: Adam Beneschan Newsgroups: comp.lang.ada Subject: Re: Equivalent of dynamic_cast (downcast) for tagged types Date: Fri, 28 Jan 2011 16:55:25 -0800 (PST) Organization: http://groups.google.com Message-ID: <105c5d90-f9a5-4193-acc3-1c701bacd53f@y19g2000prb.googlegroups.com> References: <375fb596-ab12-4cb0-a190-53d62b94b2e4@e9g2000vbi.googlegroups.com> <510d779c-d15b-4fc1-b831-bfc578ecdb4b@z3g2000prz.googlegroups.com> <7q5flc9of9ey.19h9nmmzjxqn0.dlg@40tude.net> NNTP-Posting-Host: 66.126.103.122 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: posting.google.com 1296262525 11054 127.0.0.1 (29 Jan 2011 00:55:25 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Sat, 29 Jan 2011 00:55:25 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: y19g2000prb.googlegroups.com; posting-host=66.126.103.122; posting-account=duW0ogkAAABjRdnxgLGXDfna0Gc6XqmQ User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; WOW64; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET CLR 3.5.21022; .NET CLR 3.5.30729; .NET CLR 3.0.30618; .NET4.0C),gzip(gfe) Xref: g2news1.google.com comp.lang.ada:16784 Date: 2011-01-28T16:55:25-08:00 List-Id: On Jan 28, 3:51=A0pm, "Randy Brukardt" wrote: > In both of these of these cases, there are two operations (no overriding > happens). Either one of the Foos is invisible (in which case you get the > visible one), or the program is illegal because it is ambiguous. Technically, I don't think you can get an ambiguous program from two subprograms with the same name and same profile. Either one overrides the other, as you say; or, by 8.3(12.2/2), all of them will be hidden from all visibility, and then none of the Foos is visible. Although I guess that really isn't that much different from calling it "ambiguous". -- Adam