View Compilation Error

0_0_19233141_25230.cpp: In constructor 'Node::Node(int)':
0_0_19233141_25230.cpp:21:38: error: cast from 'Node*' to 'long int' loses precision [-fpermissive]
  Node(int key) : key(key), aux((long)e & 0xffffff), size(1), l(nil), r(nil) {}
                                      ^