Second question - if I write

val foo = 0x1u

it's treated as

Int

. Is there a way to make it something else without providing a type? For example:

val foo: UByte = 0x1u

when(foo) {
    0x1u -> {} // doesn't work because 0x1u is treated as an Int
}

I can do

0x1.toUByte()

but it's ugly. Is there maybe something like

0x1ub

suffix or sth like that?

No, there can't be. One downside of type inference (in any language) is that primitive (or potentially any "built in") values can be ambiguous, so a default has to be chosen. For integral types, it's

Int

(or

UInt

with

u

suffix). it's the same reason

val x = 5

doesn't create a

Byte

unless you specify.

Makes sense, not sure if adding unsigned types to Kotlin was worth the effort. It's still a pain to code low level stuff that operates on bytes and bits.

You should realize that adding support for unsigned types wasn't the end goal, just the first step in a long (and ongoing) story. There are a number of ongoing discussions about the best way to implement operators for the various primitive types, as well as improving the whole bit fiddling experience (and lots of other low level type stuff). Hopefully it will get MUCH better with time as more of the story plays out.