Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!pasteur!ucbvax!agate!ig!uwmcsd1!leah!itsgw!sun.soe.clarkson.edu!batcomputer!cornell!deb From: deb@svax.cs.cornell.edu (David Baraff) Newsgroups: comp.lang.c++ Subject: Re: classes with no data members Keywords: sizeof,empty classes,new Message-ID: <18223@cornell.UUCP> Date: 11 Jun 88 21:51:48 GMT References: <464@polari.UUCP> <7943@alice.UUCP> <470@polari.UUCP> <10399@sol.ARPA> <472@polari.UUCP> Sender: nobody@cornell.UUCP Reply-To: deb@svax.cs.cornell.edu (David Baraff) Organization: Cornell Univ. CS Dept, Ithaca NY Lines: 19 >In article <10399@sol.ARPA>, crowl@cs.rochester.edu (Lawrence Crowl) writes: > between them without having pointers that point somewhere? In essence, by > using a NULL pointer, you have taken away my ability to do: > > p = new empty ; > q = new empty ; > if ( p != q ) .... > If 'p' and 'q' have no data in their classes (only functions), is there any difference between p and q? That is, other than looking at the addresses (i.e. p != q), is there anyway to tell p and q apart, in a functional or semantic sense? If not, then the above isn't really a problem. Though perhaps if we start discussing derived types, some differences could arise... David Baraff deb@svax.cs.cornell.edu