Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!cornell!uw-beaver!tektronix!tekcrl!tekchips!danw From: danw@tekchips.CRL.TEK.COM (Daniel E. Wilson) Newsgroups: comp.lang.c Subject: Re: pointers, tests, casts Message-ID: <3340@tekcrl.CRL.TEK.COM> Date: 30 Nov 88 22:36:12 GMT References: <11130@dartvax.Dartmouth.EDU> <494@auspex.UUCP> Sender: ftp@tekcrl.CRL.TEK.COM Lines: 17 In article <494@auspex.UUCP>, guy@auspex.UUCP (Guy Harris) writes: > >In assignments, a 0 or NULL is cast implicitly to the correct pointer > >type (I think, please correct me if I'm wrong). > > This is correct. > > >What about the '==' comparison above? Would "(ptr == 0)" get evaluated > >correctly? I tend to avoid the whole problem by defining a simple macro. Simply by using this macro always I get a NULL pointer of the needed type. This does avoid bugs. #define NIL(type) ((type *) NULL) Unless someone would like to give me warnings about the abuses of macros. 8-)