interval<T> hull(const interval<T>& a, const interval<T>& b); interval<T> intersection(const interval<T>& a, const interval<T>& b); interval<T> between(const interval<T>& a, const interval<T>& b);
Returns an interval that contains both and .
Returns an interval that is the intersection of and .
Return an interval, that is between the two given intervals. If the given intervals overlap or are unbounded the
resulting interval will be .