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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,e5eb8ca5dcea2827 X-Google-Attributes: gid103376,public From: Hyman Rosen Subject: Re: Ada OO Mechanism Date: 1999/06/08 Message-ID: #1/1 X-Deja-AN: 487230115 Sender: hymie@calumny.jyacc.com References: <7i05aq$rgl$1@news.orbitworld.net> <7i17gj$1u1k@news2.newsguy.com> <7icgkg$k4q$1@nnrp1.deja.com> <3749E9EC.2842436A@aasaa.ofe.org> <7id2eo$fag@drn.newsguy.com> <3749FF7D.F17CE16A@aasaa.ofe.org> <374AC676.F7AE0772@lmco.com> <7ieuja$5v9@news1.newsguy.com> <7ifd6l$bmf@sjx-ixn1.ix.netcom.com> <1999Jun8.151014.1@eisner> Content-Type: text/plain; charset=us-ascii X-Complaints-To: abuse@panix.com X-Trace: news.panix.com 928876996 25818 209.49.126.226 (8 Jun 1999 21:23:16 GMT) Organization: PANIX Public Access Internet and UNIX, NYC Mime-Version: 1.0 User-Agent: Gnus/5.070084 (Pterodactyl Gnus v0.84) Emacs/20.3 NNTP-Posting-Date: 8 Jun 1999 21:23:16 GMT Newsgroups: comp.lang.ada Date: 1999-06-08T21:23:16+00:00 List-Id: kilgallen@eisner.decus.org (Larry Kilgallen) writes: > The fact that GNAT allocates it in one place does not mean all compilers > will do it in the same place. Is your question specifically "how does > GNAT do this ?" ? I am trying to understand the mechanism behind T'Class. I have been told that the size of such variables is determined at run-time, and also that the heap is not required for such variables. So, to anyone, if you don't mind taking the time to explain, how does implement this? Also, I stated in an earlier message that I thought not allowing T'Class variables in records was not orthogonal, but understandable in light of the above. Now, suppose I need a function that returns a pair of values, one of which is a T'Class and the other a boolean. Is there a way to do this? I can't return a record containing the pair, because I can't have such a record. I assume that a procedure with a pair of out parameters won't work, because the T'Class variable which receives the output must be initialized when declared, and then its tag can't change. So, is there a way?