ensureNeverFrozen

fun Any.ensureNeverFrozen()(source)

import kotlin.native.concurrent.*

fun main() {
    // Any object can be protected from freezing
    val counter = Counter()
    counter.ensureNeverFrozen()

    // Trying to freeze it will throw an exception
    try {
        counter.freeze()
    } catch (e: IllegalStateException) {
        println("Cannot freeze: ${e.message}")
    }
}

class Counter {
    var value = 0
}