wat.swift

protocol TypeEquality {
  typealias From
  typealias To
  func apply(a: From) -> To
}

struct Refl<X> : TypeEquality {
  typealias From = X
  typealias To = X
  func apply(a: From) -> To {
    return a
  }
}

extension Array {
  func plusEverything<Ev: TypeEquality where Ev.From == T, Ev.To == Int>(ev: Ev, n: Int) -> Array<Int> {
    return self.map({ ev.apply($0) + n })
  }
}

let x = [true]

println([true,false].plusEverything(Refl(), n:5))
println([1,2,3].plusEverything(Refl(), n:5))