Example of Swift Type Casting Chaining

TypeCastingChaining.swift

//: Playground - noun: a place where people can play

var dict = [ "user" : ["attribute" : "attribute_value"] ]

if let d = dict as? [String : AnyObject],
   let user_d = d["user"] as? [String : String] {
  print(user_d)
} else {
  print("Didn't work.")
}