let somePoint = (1, 1)switch somePoint {case (0, 0):    println("(0, 0) is at the origin")case (_, 0)://使用下划线(underscore)代表任何可能的值    println("(\(somePoint.0), 0) is on the x-axis")case (0, _):    println("(0, \(somePoint.1)) is on the y-axis")case (-2...2, -2...2):    println("(\(somePoint.0), \(somePoint.1)) is inside the box")default:    println("(\(somePoint.0), \(somePoint.1)) is outside of the box")//prints "(1, 1) is inside the box"

let anotherPoint = (2, 0)switch anotherPoint {case (let x, 0):　　println("on the x-axis with an x value of \(x)")case (0, let y):　　println("on the y-axis with a y value of \(y)")case let (x, y):　　println("somewhere else at (\(x), \(y))")}

let yetAnotherPoint = (1, -1)switch yetAnotherPoint {case let (x, y) where x == y:　　println("(\(x), \(y)) is on the line x == y")case let (x, y) where x == -y:　　println("(\(x), \(y)) is on the line x == -y")case let (x, y):　　println("(\(x), \(y)) is just some arbitrary point")}// prints "(1, -1) is on the line x == -y"