Overloading Swift functions with only return type.

gistfile1.swift

func f (x: Int) -> Int {
  return 1 + x + x*x
}

func f (x: Int) -> String {
  return "result = \(f(x) as Int)"
}

// awesome!
var x: Int = f(2)    // 7
var y: String = f(2) // "result = 7"

// sweet!
var z = f(2)         // Error: Ambiguous use of 'f'


// is type inferred by composition?
func square (x: Int) -> Int {
  return x * x
}
square(f(2)) // 49 ... it is!