RWTValHashMapIterator(3C++)

Name
     RWTValHashMapIterator<K,T,H,EQ> - Rogue Wave library class

Synopsis
              #include<rw/tvhdict.h>



              RWTValHashMap<K,T,H,EQ> m;
          RWTValHashMap<K,T,H,EQ> itr(m);

Please Note!
     If you have the Standard C++ Library, use the interface described here.
     Otherwise, use the interface for RWTValHashDictionaryIterator described
     in Appendix A.






Description
     RWTValHashMapIterator is supplied with Tools 7 to provide an iterator
     interface to RWTValHashMapIterator that has backward compatibility with
     the container iterators provided in Tools 6. Iteration over an
     RWTValHashMap is pseudorandom and dependent on the capacity of the
     underlying hash table and the hash function being used.  The only useable
     relationship between consecutive elements is that elements which are
     defined to be equivalent by the equivalence object, EQ, will remain
     adjacent.  The current item referenced by this iterator is undefined
     after construction or after a call to reset().  The iterator becomes
     valid after being advanced with either a preincrement or an operator().
     For both operator++ and operator(), iterating past the last element will
     return a value equivalent to boolean false.  Continued increments will
     return a value equivalent to false until reset() is called.

Persistence
     None

Example
              #include<rw/tvhdict.h>



              #include<iostream.h>
          #include<rw/cstring.h>


              struct silly_h{

                 unsigned long operator()(const RWCString& x) const
             { return x.length() * (long)x(0); }
          };


              int main(){



                 RWTValHashMap
               <RWCString,int,silly_h,equal_to<RWCString> > age;
             RWTValHashMapIterator
               <RWCString, int, silly_h, equal_to<RWCString > > itr(age);


                 age.insert(RWCString("John"), 30);



                 age.insert(RWCString("Steve"),17);
             age.insert(RWCString("Mark"),24);


              //Duplicate insertion rejected



                 age.insert(RWCString("Steve"),24);



                 for(;itr();)



                   cout << itr.key() << "'s age is " << itr.value() << endl;



                 return 0;



              }



              Program Output (not necessarily in this order)

              John's age is 30
          Steve's age is 17
          Mark's age is 24

Public Constructors
              RWTValHashMapIterator<K,T,H,EQ>



              (RWTValHashMap<K,T,H,EQ>&h);






     Creates an iterator for the hashmap h.  The iterator begins in an
     undefined state and must be advanced before the first element will be
     accessible.

Public Member Operators
              RWBoolean
          operator()();


     Advances self to the next element. Returns false if the iterator has
     advanced past the last item in the container and true otherwise.

              RWBoolean
          operator++();


     Advances self to the next element.  If the iterator has been reset or
     just created self will now reference the first element.  If, before
     iteration, self referenced the last association in the multimap, self
     will now reference an undefined value and false will be returned.
     Otherwise, true is returned. Note: no postincrement operator is provided.

Public Member Functions
              RWTValHashMap<K,T,H,EQ>*
          container() const;


     Returns a pointer to the collection being iterated over.

              K
          key() const;


     Returns the key portion of the association currently pointed to by self.
              void
          reset();
          void
          reset(RWTValHashMap<K,T,H,EQ>& h);


     Resets the iterator so that after being advanced it will reference the
     first element of the collection.  Using reset() with no argument will
     reset the iterator on the current container.  Supplying a RWTValHashMap
     to reset() will reset the iterator on that container.

              T
          value();


     Returns the value portion of the association referenced by self.