作为 Swift 5 最值得期待的新功能之一，Result 类型该如何使用？

public enum Result<Success, Failure: Error> {  /// A success, storing a `Success` value.  case success(Success)
   /// A failure, storing a `Failure` value.  case failure(Failure)  ...}

enum AnErrorType: Error {    case failureReason1    case failureReason2}
func failableFunction() -> Result<Int, AnErrorType> {
    ...    if (errorCondition1) {        return .failure(.failureReason1)    }    ...    return .success(1)}
func callFailableFunction() {
    ...    let result = failableFunction()    switch result {    case .success(let integerResult):        ...    case .failure(let error):        switch error {        case .failureReason1:            ...        case .failureReason2:            ...        }    }    ...}

let result = Result { try String(contentsOfFile: configuration) }

asyncOperationCall() { (value, error) in
    guard error != nil else { self.handleError(error!) }    self.handleValue(value)}

do {    handleOne(try String(contentsOfFile: oneFile))} catch {    handleOneError(error)}
do {    handleTwo(try String(contentsOfFile: twoFile))} catch {    handleTwoError(error)}
do {    handleThree(try String(contentsOfFile: threeFile))} catch {    handleThreeError(error)}

let one = Result { try String(contentsOfFile: oneFile) }let two = Result { try String(contentsOfFile: twoFile) }let three = Result { try String(contentsOfFile: threeFile) }
handleOne(one)handleTwo(two)handleThree(three)