Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!umd5!ncifcrf!nlm-mcs!brl-adm!brl-smoke!gwyn From: gwyn@brl-smoke.ARPA (Doug Gwyn ) Newsgroups: comp.lang.c Subject: Re: Structure pointer question Message-ID: <8185@brl-smoke.ARPA> Date: 29 Jun 88 17:00:38 GMT References: <361@teletron.uucp> <8074@brl-smoke.arpa> <4524@haddock.isc.com> <5925@aw.sei.cmu.edu> <389@proxftl.UUCP> Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB)) Organization: Ballistic Research Lab (BRL), APG, MD. Lines: 8 In article <389@proxftl.UUCP> bill@proxftl.UUCP (T. William Wells) writes: >The C standard should make that explicit, don't you think? It's been known for many years that the logic of C requires that structure pointers all "smell the same" in a certain sense (for example, in the context of sizeof). However, they definitely do NOT have to have the same representation. For example, in a C interpreter they could contain tag information that could be used to distinguish between them (presumably to detect usage errors).