_INSTANTIATING CODE PATTERNS_
by Fred Wild

Listing Three

#ifndef pets_H
#define pets_H

// Forward references for each class

class  PetOwner ;
class  Veterinarian ;
class  Pet ;

//  Class PetOwner --------------------------------
class PetOwner {
       string                  m_Name ;
       Pet                    *m_Pet ;
       Veterinarian           *m_Vet ;
   public:
       PetOwner();
       PetOwner(const PetOwner& obj);
       PetOwner *makeCopy() const ;
       virtual ~PetOwner();

       PetOwner &operator=(const PetOwner &rhs) ;

       const string &             GetName () const ;
       void                       SetName (const string & val) ;

       const Pet *                GetPet () const ;
       void                       SetPet (Pet *val) ; 
       void                       ClearPet () ; 

       const Veterinarian *       GetVet () const ;
       void                       SetVet (Veterinarian *val) ; 
       void                       ClearVet () ; 
} ;

//  Class Veterinarian --------------------------------
class Veterinarian {
       string                  m_Name ;
       string                  m_StreetAddress ;
       string                  m_Town ;
       string                  m_Phone ;
   public:
       Veterinarian();
       Veterinarian(const Veterinarian& obj);
       Veterinarian *makeCopy() const ;
       virtual ~Veterinarian();

       Veterinarian &operator=(const Veterinarian &rhs) ;

       const string &             GetName () const ;
       void                       SetName (const string & val) ;

       const string &             GetStreetAddress () const ;
       void                       SetStreetAddress (const string & val) ;

       const string &             GetTown () const ;
       void                       SetTown (const string & val) ;

       const string &             GetPhone () const ;
       void                       SetPhone (const string & val) ;
} ;

//  Class Pet --------------------------------
class Pet {
       string                  m_Name ;
       string                  m_KindOfPet ;
   public:
       Pet();
       Pet(const Pet& obj);
       Pet *makeCopy() const ;
       virtual ~Pet();

       Pet &operator=(const Pet &rhs) ;

       const string &             GetName () const ;
       void                       SetName (const string & val) ;

       const string &             GetKindOfPet () const ;
       void                       SetKindOfPet (const string & val) ;
} ;
#endif