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,ec21c3c7cdc7ff3e X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news2.google.com!news4.google.com!newsfeed2.dallas1.level3.net!news.level3.com!newsfeed-00.mathworks.com!nntp.TheWorld.com!not-for-mail From: Robert A Duff Newsgroups: comp.lang.ada Subject: Re: private types Date: 20 Mar 2006 10:19:30 -0500 Organization: The World Public Access UNIX, Brookline, MA Message-ID: References: <1142279908.327131.230200@j52g2000cwj.googlegroups.com> <1259548.CMTukHGvVZ@linux1.krischik.com> <1172812.9zPbPKbdVq@linux1.krischik.com> NNTP-Posting-Host: shell01.theworld.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: pcls4.std.com 1142867970 11909 192.74.137.71 (20 Mar 2006 15:19:30 GMT) X-Complaints-To: abuse@TheWorld.com NNTP-Posting-Date: Mon, 20 Mar 2006 15:19:30 +0000 (UTC) User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 Xref: g2news1.google.com comp.lang.ada:3491 Date: 2006-03-20T10:19:30-05:00 List-Id: Maciej Sobczak writes: > but still, (void*)0 == NULL will always evaluate to true, even if the > internal representation of the null pointer is not zero. Are you sure? Are you talking about C or C++ or both? Does (void*)x always return NULL if x is an appropriate-sized integer whose value is zero? That would require run-time overhead if NULL is not represented as all-zero-bits. On the other hand, it's pretty confusing if casting zero to (void*) is sometimes guaranteed to return NULL, and sometimes not, depending on whether the zero value is known at compile time. - Bob