From: wiseb@colossus.cs.rpi.edu (Bowden Wise)
Subject: Deriving from class Object with OWL
Organization: Rensselaer Polytechnic Institute Computer Science, Troy NY
Lines: 30
Distribution: comp
NNTP-Posting-Host: colossus.cs.rpi.edu

I am trying to define my own class derived from the Object class so
that I may insert them into a HashTable (a class provided by the
Container class library).

I have defined all of the pure virtual functions of Object, but I
still get an error when I attempt to allocate a HashEntry object:

  Cannot create instance of abstract class HashEntry

Has anyone derived from class Object before?  What have I left out?
Here are the virtual functions that I defined from Object:

virtual classType      isA()   const { return hashEntryClass; }
virtual Pchar          nameOf()const { return "HashEntry"; }

virtual hashValueType hashValue() const { return hashValue(hWindow); }
// Note: hWindow is defined in HashEntry

virtual int            isEqual (const Object _FAR &obj) const
{ return this == &(HashEntry&) obj; }

virtual void           printOn( Rostream os) const
{
 os << "[ HWindow is " << (void _FAR *) hWindow << " ]\n"; 
}
--
--------------------------------------------------------------------
- Bowden Wise
  Computer Science Dept, Rensselaer Polytechnic Inst, Troy, NY 12180
  internet: wiseb@cs.rpi.edu
