struct S : ExpressibleByFloatLiteral {
  init(floatLiteral: FloatLiteralType) {}
}

typealias AssocTy = Int

protocol P {
  associatedtype AssocTy
  func foo(x: AssocTy)
}

class C : P {
  func foo(x: AssocTy) {}
}

C.AssocTy.self == Int.self // true