kotlin infix

infix fun Int.add(x: Int): Int {
    return this + x
}

fun () {
    val result = 100 add 200
    println(result)
}

class Account(
        private var balance: Double = 0.0
) {
    infix fun add(amount: Double): Double {
        return this.balance.plus(amount)
    }
}

fun () {
    val account = Account(10.0)
    
    val result = account add 1.0
    println(result)
}