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=-0.8 required=5.0 tests=BAYES_00,INVALID_DATE autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,93fa00d728cc528e X-Google-Attributes: gid103376,public X-Google-Thread: 1108a1,93fa00d728cc528e X-Google-Attributes: gid1108a1,public X-Google-ArrivalTime: 1994-10-17 11:26:32 PST Newsgroups: comp.lang.ada,comp.object Path: bga.com!news.sprintlink.net!hookup!ames!lll-winken.llnl.gov!noc.near.net!inmet!dsd!bobduff From: bobduff@dsd.camb.inmet.com (Bob Duff) Subject: Re: SOLVED! Decoupled Mutual Recursion Challenger Message-ID: Sender: news@inmet.camb.inmet.com Organization: Intermetrics, Inc. References: <1994Oct12.224944.25566@swlvx2.msd.ray.com> <1994Oct17.154812.9104@swlvx2.msd.ray.com> Date: Mon, 17 Oct 1994 17:55:26 GMT Xref: bga.com comp.lang.ada:7012 comp.object:7459 Date: 1994-10-17T17:55:26+00:00 List-Id: In article <1994Oct17.154812.9104@swlvx2.msd.ray.com>, John Volan wrote: >In article <1994Oct12.224944.25566@swlvx2.msd.ray.com> I (John Volan) wrote: >> (Er ... I've been scouring the RM9X 5.0 and much to my surprise I can't >> seem to find positive confirmation for the fact that System.Address will >> have the same bit-representation as access types. Tucker, if you're >> listening, can you give me a hand here?) > >Actually, there wasn't any need to involve System.Address after all. >A better solution would be to just declare Identity.Value as an access >type pointing to some "dummy" designated type. There is no requirement that type Address have the same representation as an access type. In fact, there is no requirement that one access type have the same representation as another access type. There are, in fact, compilers that take advantage of this. I believe that GNAT, for example, stores access-to-unconstrained-arrray differently from access-to-integer. However, there are some conversions operations back and forth between Address and any given access type. See RM9X-13.7.1;5.0. These aren't completely portable, either, but they are likely to be in the "simple" cases. - Bob -- Bob Duff bobduff@inmet.com Oak Tree Software, Inc. Ada 9X Mapping/Revision Team (Intermetrics, Inc.)