Destructuring in when

Language Design
9

To not create temprorary objects, I propose following syntax:

when (obj) {
    is Pair<*, *> -> when((k, v) *obj) {
        (1, "5") -> ... //  k, v available here
        ("asdfa", true) -> ...
        (variable, _) -> ...
    }
}

if ((k, v) *obj == ("asdfa", 42) {
    // k, v available here
}

and would be nice to see matched value as it

when (obj) {
    is Pair<*, *> -> when((k, v) *obj) {
        (1, "5") -> it::run { println("[$key=$value]") }
    }
}

with => arrow to make it available as this

(1, "adfa") => println("[$key=$value]")