Operator overloading

Unary prefix operators

                  data class Point(val x: Int, val y: Int)
​
operator fun Point.unaryMinus() = Point(-x, -y)
​
val point = Point(10, 20)
​
fun main() {
   println(-point)  // prints "Point(x=-10, y=-20)"
}
                

                    data class Point(let x: Int, let y: Int)
​
operator func Point.unaryMinus() = Point(-x, -y)
​
let point = Point(10, 20)
​
func main() {
   print(-point)  // prints "Point(x=-10, y=-20)"
}