let array = ["zero", "one", "two", "three"]
let dict = Dictionary(uniqueKeysWithValues: array.enumerated())
// error: Generic parameter 'Key' could not be inferred

let array = ["zero", "one", "two", "three"]
let dict = Dictionary(array.enumerated(), uniquingKeysWith: { $1 })
// error: Generic parameter 'Key' could not be inferred

typealias Pair = (a: Int, b: String)

let seq = AnySequence<Pair>([(1, "one")])
let dict = Dictionary(uniqueKeysWithValues: seq)
// Generic parameter 'Key' could not be inferred

typealias Pair = (Int, String)

let seq = AnySequence<Pair>([(1, "one")])
let dict = Dictionary(uniqueKeysWithValues: seq)
print(dict) // [1: "one"]