Key Set Iterators ( KeySet::const_iterator )

Definition

Instances of type it iterate over the elements of a key set. They behave similar to const-pointers to AgdKey. The elements of a key set are always in the same order as the keys in its keymapper. A key set S provides functions to retrieve iterators pointing to the first or last element of S. We say an iterator of key set S is valid iff it points to an element of S. Derefferencing is only allowed for valid iterators.

#include < AGD/KeySet.h >

Creation

KeySet::const_iterator	it	creates an invalid iterator it.
KeySet::const_iterator	it(const KeySet& S)	creates an iterator it pointing to the first element of S.
KeySet::const_iterator	it(const const_iterator& iter)
		creates an iterator identical to iter.

Operations

bool	it.valid()	returns true iff it is valid, i.e., points to an element.
bool	it == const const_iterator& iter
		returns true iff it and iter point to the same element.
bool	it != const const_iterator& iter
		returns true iff it and iter point to different elements.
const_iterator &	it = const const_iterator& iter
		assigns iter to it.
const AgdKey &	*it	returns the element to which it points.
const AgdKey *	it->	returns the address of the element to which it points.
const_iterator &	++it	increments and returns it.
const_iterator	it++	increments it and returns its previous value.
const_iterator &	-it	decrements and returns it.
const_iterator	it-	decrements it and returns its previous value.

Example

The following examples shows, how to use key set iterators in order to iterate over all elements of a key set. The second loop iterates in reverse order and demonstrates the use of operator->.

void write_set (const KeySet &S)
{
  KeySet::const_iterator it;

  // iteration over all elements of S
  for (it = S.begin(); it != S.end(); ++it) {
    cout << *it << endl;
  }

  // iteration in reverse order
  for (it = S.rbegin(); it != S.rend(); --it) {
    cout << it->index() << endl;
  }
}