Returns true . Sets self to the intersection of self and s . Elements from each set are dereferenced before being compared. Returns true if there is set equivalence between self and s , and returns false otherwise. Returns rwnil if there is no such element.
Returns rwnil if there is no such element.
Returns the number of items removed. Returns the number of items removed. Elements from each set are dereferenced before being compared. Elements from each set are dereferenced before being compared. If a collection is created off the heap, then you are responsible for deleting it.