What is the purpose of the 'Nothing' construct in Kotlin?

In Kotlin, the Nothing type is used to denote a function or expression that never returns a value (for example, it always throws an exception or runs infinitely). This allows the compiler to understand that the code will not continue after such a function call.

Example:

fun fail(message: String): Nothing {
    throw IllegalArgumentException(message)
}

fun example() {
    val x: Int = fail("Error") // Here, the compiler understands that the function will not return a value
}

Nothing is useful for functions that do not terminate normally and helps improve flow control and type safety.