Path: utzoo!attcan!uunet!husc6!bloom-beacon!tut.cis.ohio-state.edu!cs.utexas.edu!ut-sally!ut-emx!mybest!bigtex!juniper!bloom!bobd From: bobd@bloom.UUCP (Bob Donaldson) Newsgroups: comp.lang.c++ Subject: Re: classes with no data members Summary: semantics Keywords: sizeof,empty classes,new Message-ID: <423@bloom.UUCP> Date: 22 Jun 88 15:40:42 GMT References: <464@polari.UUCP> <7943@alice.UUCP> <470@polari.UUCP> <10399@sol.ARPA> <18223@cornell.UUCP> Lines: 20 In article <18223@cornell.UUCP>, deb@svax.cs.cornell.edu (David Baraff) writes: > > 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. If we are getting into semantics, here, it is certainly possible (and possibly helpful :-)) to distinguish between two DIFFERENT yet otherwise indistinguishable instances of a type. The fact that they are different instances itself may be of some value, even if no difference would arise from choosing one over the other for a given purpose. ---------------------------------------------------------------- Bob Donaldson ...!ut-emx!juniper!radian!bobd Radian Corporation ...!sun!texsun!radian!bobd PO Box 201088 Austin, TX 78703 (512) 454-4797 Views expressed are my own, not necessarily those of my employer.