Also

@ExperimentalUnsignedTypes
fun main(args: Array<String>) {
    var a: UByte = 0u
    println(--a) // -1
}

but

@ExperimentalUnsignedTypes
fun main(args: Array<String>) {
    var a: UByte = 0u
    --a
    println(a)  // 255
}

Does

println()

accepts UByte?

println((--a).toString())

works fine 🙂

That's why they are called

ExperimentalUnsignedTypes

, not everything is smooth, especially in the first preview.

Just bringing it to peoples attention, not meaning to be negative. I have been looking forward to unsigned types for a long time 🙂

I've checked, it hasn't been fixed yet in the development branch, so I've opened https://youtrack.jetbrains.com/issue/KT-26219

I had opened an issue as well, if you spot it could you close it? 🙂