RWTValHashSetIterator(3C++) RWTValHashSetIterator(3C++)
Name
RWTValHashSetIterator<T,H,EQ> - Rogue Wave library class
Synopsis
#include<rw/tvhset.h>
RWTValHashSet<T,H,EQ> m;
RWTValHashSetIterator<T,H,EQ> itr(m);
Please Note!
If you have the Standard C++ Library, use the interface described here.
Otherwise, use the restricted interface to RWTValHashTableIterator
described in Appendix A.
DescriptionRWTValHashSetIterator is supplied with Tools.h++ 7 to provide an iterator
interface to RWTValHashSetIterator that is backward compatible with the
container iterators provided in Tools.h++ 6.x. Iteration over an
RWTValHashSet 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 pre-increment 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/tvhset.h>
#include<rw/cstring.h>
#include<iostream.h>
struct silly_h{
Page 1
RWTValHashSetIterator(3C++) RWTValHashSetIterator(3C++)
unsigned long operator()(const RWCString& x) const
{ return x.length() * (long)x(0); }
};
int main(){
RWTValHashSet <RWCString, silly_h,equal_to<RWCString> > age;
RWTValHashSetIterator
<RWCString, silly_h, equal_to<RWCString > > itr(age);
age.insert("John");
age.insert("Steve");
age.insert("Mark");
//Duplicate insertion rejected
age.insert("Steve");
for(;itr();) cout << itr.key() << endl;
return 0;
}
Program Output (not necessarily in this order)
John
Steve
Public Constructors
Mark
RWTValHashSetIterator<T,H,EQ> (RWTValHashSet<T,H,EQ>&h);
Creates an iterator for the hashset 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 value in the multi-set, self will now
reference an undefined value and false will be returned. Otherwise, true
Page 2
RWTValHashSetIterator(3C++) RWTValHashSetIterator(3C++)
is returned. Note: no postincrement operator is provided.
Public Member Functions
RWTValHashSet<T,H,EQ>*
container() const;
Returns a pointer to the collection being iterated over.
T
key() const;
Returns the value currently pointed to by self.
void
reset();
void
reset(RWTValHashSet<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 RWTValHashSet
to reset() will reset the iterator on that container.
Page 3
