Xcode 7 beta 4 is available today with the latest revision to Swift 2.0. Along with indirect enums, beta 4 includes some significant changes to the standard library, including:

• The protocol hierarchy for sequences and collections has been overhauled, with subscripting moved from CollectionType to a new Indexable protocol. This change, along with the addition of a SubSequence type alias inside CollectionType, sees the end of the Sliceable protocol and the introduction of a new Slice struct that can be based on any indexable instance.

• As noted in the release notes, SinkType and SinkOf are now gone, being replaced by (T) -> () closures in the few relevant functions and methods.

• The list of free functions is getting leaner and leaner as functions move into protocol extensions. The extensible and range-replaceable collection have shuffled off their mortal coil this time (along with ExtensibleCollectionType itself).