Update function prototype in docs for shared examples
Update function prototype in docs for shared examples

- It was not fully up-to date for Swift 3 GM and as such would fail to
  compile if compiled as-is.
DanielAsher/Quick,phatblat/Quick,phatblat/Quick,phatblat/Quick,Quick/Quick,dgdosen/Quick,dgdosen/Quick,jeffh/Quick,dgdosen/Quick,jeffh/Quick,jeffh/Quick,Quick/Quick,Quick/Quick,phatblat/Quick,DanielAsher/Quick,Quick/Quick