try.swift

extension Optional {
    func try<U>(f: (T) -> U) -> Optional<U> {
        if let unwrapped = self {
            return f(unwrapped)
        } else {
            return nil
        }
    }
}


func formatLegCount(legCount: Int) -> String {
    return "It has \(legCount) legs"
}

let numberOfLegs = ["ant": 6, "snake": 0, "cheetah": 4]
let possibleLegCount = numberOfLegs["ant"]
let possibleString:Optional<String> = possibleLegCount.try(formatLegCount)