examples for an article

1.GuardBlackSheep

func g<T>(array: [T], at index: Int, file: StaticString = #file, line: UInt = #line) -> T {
    continueAfterFailure = false
    guard index < array.count else {
        XCTFail("index out of range", file: file, line: line)
        precondition(false)
    }
    return array[index]
}