[Pitch] Method Key Paths

[Alejandro (Alejandro Alonso)]

@amritpan

struct Calculator {
  func square(of number: Int) -> Int {
    return number * number * multiplier
  }

  func cube(of number: Int) -> Int {
    return number * number * number * multiplier
  }

  init(multiplier: Int) {
    self.multiplier = multiplier
  }

  let multiplier: Int
}

// Key paths to Calculator methods
let squareKeyPath = \Calculator.square
let cubeKeyPath = \Calculator.cube

What happens when Calculator has properties (stored or computed) that have the names square and/or cube? I assume this is just an ambiguous error? In my opinion, I think we need to abandon the name form of referencing functions and require the parenthesis with arguments labels so that there's no form of ambiguity.