Arthur Ariel Sabintsev on Medium:

Apple explicitly states in their Swift iBook that the String class is bridged seamlessly to the NSString class and can make use of its APIs, however, the length method doesn’t exist. That’s because unicode characters in Swift don’t all take up the same unit of storage in memory, and therefore calling NSString’s length , which is based on 16-bit code units, on a Swift String, wont work.

I just don’t have the patience for this kind of stuff anymore.