Is it possible to create extension constructors in Kotlin?

Question

In other languages like Swift, there is the possibility of creating a function extension that adds a new constructor.

Something like this:

// base c         


        

Answer 1

Based on @s1m0nw1 solution, I can adjust it to be more like the OP wanted by overriding operator invoke.

// base class
class Whatever() {
    companion object {
        fun setPotato(potato: String)
    }
}

operator fun Whatever.Companion.invoke(potato: String) {
    setPotato(potato)
}

fun main(args: Array) {
    println(Whatever("holi"))
}

Keep in mind that it still needs companion object inside base class. If you can't edit the source of base class (in case of kotlin framework class or third party class), and if it already has companion object that you want to add your new method to, you can always use an extension function:

fun Int.Companion.setPotato(potato: String) {
    // ...
}