Returns the int id of the given element (0-based) or -1 if not found in the index.
Returns the indexed items along with their indicies
Returns Some(t) if this int corresponds to some object, and None otherwise.
Returns true if this index contains the element t.
Returns an object at the given position or throws IndexOutOfBoundsException if it's not found.
Override Iterable's linear-scan indexOf to use our apply method.
Returns Some(i) if the object has been indexed, or None.
(Changed in version 2.9.0) The behavior of
scanRight has changed. The previous behavior can be reproduced with scanRight.reverse.
(Changed in version 2.9.0)
transpose throws an
IllegalArgumentException if collections are not uniformly sized.