Getting a vertex_handle from an edge_iterator

I'm having quite some difficulty getting a vertex_handle for each of the end points of an edge in a Delaunay triangulation. Since I hammered my head against this for several hours I thought maybe one of you guys could help me out with this apparently trivial problem:

#include <iostream>

#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Delaunay_triangulation_2.h>

using namespace std;

typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
typedef CGAL::Delaunay_triangulation_2<K> Triangulation;
typedef Triangulation::Point Point;
typedef Triangulation::Edge_iterator Edge_iterator;
typedef Triangulation::Vertex_handle Vertex;

int main(){
  Point p;
  Triangulation t;
  while(cin >> p)
    t.insert(p);

  // Iterate over edges
  for(Edge_iterator ei=t.finite_edges_begin();ei!=t.finite_edges_end(); ei++){
    // Get a vertex from the edge
    Vertex vs = ei->source();
  }
}

According to the documentation dereferencing an Edge_iterator I should get an Edge_handle and Edge_handle should have members source() and target() to simply get the endpoints, but it won't compile and seems to be wrong. Derefencing like above will give me a pair<> which doesn't have those member functions.

Any idea what I'm doing wrong?