Tuples as function arguments, part 3

Tuple_otherRules.swift

//Default value
func sum4(x: Int, y: Int, maybe: Int = 1) -> Int {
  return x + y + maybe
}

let params4 = (1, 5, 1)
let params4_1 = (1, 5, maybe: 1)

sum4(1, 5, maybe: 1)
sum4(1, 5)

sum4(params4) //Fails
sum4(params4_1) //Fails

// Optional
func sum5(x: Int, y: Int, maybe: Int?) -> Int {
  return x + y + (maybe ?? 0)
}

let params5 = (1, 5, 3)
let params5_1 = (1, 5, Optional<Int>.None)

sum5(params5) //Fails, 3 is not optional
sum5(params5_1)

struct A {

  func sum(x: Int, y: Int) { }
  static func sum1(x: Int, y: Int) { }
}

let aParams = (1, y:4)

let a = A()
a.sum(aParams)
A.sum1(aParams)

// inline Tuples
a.sum((1, y:1)) // Fails