How can you check, if a class has an initializer for a lateinit variable, when this class is passed as variable to another class?

class Config {
    lateinit var s: String
}
class Consumer(val config: Config) {
    init {
         require(config::s.isInitialized)
    }
}

My current workaround is using an internal member function:

fun isInitialized() = ::s.isInitialized

and call this function in

require

.

class Config(var s: String)

can ensure that

s

must have a value

@Arxing Lin what is the point of

Delegates.notNull

? How is it different from lateinit var?