Kotlin iterator to list?

Probably the easiest way is to convert iterator to Sequence first and then to List:

listOf(1,2,3).iterator().asSequence().toList()

result:

[1, 2, 3]

I would skip the conversion to sequence, because it is only a few lines of code.

fun <T> Iterator<T>.toList(): List<T> =
    ArrayList<T>().apply {
        while (hasNext())
            this += next()
    }

---

Update:

Please keep in mind though, that appending to an ArrayList is not that performant, so for longer lists, you are better off with the following, or with the accepted answer:

    fun <T> Iterator<T>.toList(): List<T> =
        LinkedList<T>().apply {
            while (hasNext())
                this += next()
        }.toMutableList()