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=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!gandalf.srv.welterde.de!news.jacob-sparre.dk!loke.jacob-sparre.dk!pnx.dk!.POSTED!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: Incomplete types used with generics Date: Mon, 11 May 2015 20:43:54 -0500 Organization: Jacob Sparre Andersen Research & Innovation Message-ID: References: <830c0323-a06c-4884-9214-89f3ee6f17b5@googlegroups.com> NNTP-Posting-Host: rrsoftware.com X-Trace: loke.gir.dk 1431395034 23437 24.196.82.226 (12 May 2015 01:43:54 GMT) X-Complaints-To: news@jacob-sparre.dk NNTP-Posting-Date: Tue, 12 May 2015 01:43:54 +0000 (UTC) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.5931 X-RFC2646: Format=Flowed; Original X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Xref: news.eternal-september.org comp.lang.ada:25828 Date: 2015-05-11T20:43:54-05:00 List-Id: "Jeremiah" wrote in message news:830c0323-a06c-4884-9214-89f3ee6f17b5@googlegroups.com... > One of the things I read about with ada2012 is the ability to use > incomplete types > as generic parameters. However, I am having some trouble implementing > them. ... > What am I missing? You missed at least 6 months of wrestling with various AdaCore people about this feature, specifically over some proposed ACATS tests. (Most of the tests showed lovely GNAT bug boxes.) They were trying very hard to find reasons that the tests were illegal, because there was an problem with the design of their implementation that made the tests very hard to implement. They managed to uncover some language problems that will probably be fixed someday, but in particular, everyone eventually agreed that the test using limited with (CC51010) is correct (now). I've heard that they've fixed the compiler so that test works, so you'll probably be able to get that to work at some future point (but surely not with GNAT GPL 2014, which clearly predates the fixes). I suspect that you ran afoul of the fact that the freezing rules differ for tagged incomplete vs. untagged incomplete types, but even if you fixed that you'd still be very likely to run into problems with current GNAT versions unless you are a GNAT PRO user and can get a wavefront. I'd suggest trying this again next year. Randy.