#include <RelKey.h>
The RelKey class is used by the Relation class to relate events data. It contains four pointers: one points to a particular event data, another points to the next relation containing the same data pointer, one another points to the previous relation and the fourth one points to the first relation not containing the same data pointer. This information is useful to efficiently search for all relations involving a particular event data or to remove a relation.
1.4.7