A non-null property delegate

The Kotlin framework is quite rich; it provides support for a delegated property for non-null values. All you have to do is use Delegates.nonNull, like in this simple example:

    class NonNullProp { 
      var value: String by Delegates.notNull<String>() 
    } 
 
    val nonNull = NonNullProp() 
    nonNull.value = "Kotlin rocks" 
    println("Non null value is: ${nonNull.value}") 
 
    //this will not compile 
    nonNull.value = null

Trying to access the property value before it has been initialized would lead to an IllegalStateException being raised. Furthermore, if you try to set a null to it, you will get a compilation error.