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: 109fba,b87849933931bc93 X-Google-Attributes: gid109fba,public X-Google-Thread: fac41,b87849933931bc93 X-Google-Attributes: gidfac41,public X-Google-Thread: f43e6,b87849933931bc93 X-Google-Attributes: gidf43e6,public X-Google-Thread: 114809,b87849933931bc93 X-Google-Attributes: gid114809,public X-Google-Thread: 1108a1,b87849933931bc93 X-Google-Attributes: gid1108a1,public X-Google-Thread: 103376,b87849933931bc93 X-Google-Attributes: gid103376,public From: Ken Garlington Subject: Re: OO, C++, and something much better! Date: 1997/01/15 Message-ID: <32DCFB78.605A@lmtas.lmco.com>#1/1 X-Deja-AN: 209988527 references: <32DA822A.2FD8@lmtas.lmco.com> content-type: text/plain; charset=us-ascii organization: Lockheed Martin Tactical Aircraft Systems mime-version: 1.0 newsgroups: comp.lang.c++,comp.lang.smalltalk,comp.lang.eiffel,comp.lang.ada,comp.object,comp.software-eng x-mailer: Mozilla 3.01 (Win95; U) Date: 1997-01-15T00:00:00+00:00 List-Id: Robert Dewar wrote: > > Ken Garlington wrote > > " type My_Integer is new Integer; > function To_Int is new Unchecked_Conversion ( My_Integer, Integer );" > > Why on earth use an unchecked conversion here when a perfectly ordinary, > and completely safe type conversion will work just fine? Because then it wouldn't demonstrate the use of an unchecked conversion, would it? (I _knew_ someone was going to ask that. :) Anyway, if it didn't already get posted, the example is wrong. It works with GNAT 3.05, but is flagged as a compile-time error in 3.07. However, via access values, an unchecked conversion could still be used without creating a copy, so the comment is still valid: using address specs to create an overlay should not be significantly less/more safe than unchecked_conversion, at least not for the reason originally given... -- LMTAS - The Fighter Enterprise - "Our Brand Means Quality" For job listings, other info: http://www.lmtas.com or http://www.lmco.com