I think it would be really useful if Kotlin supported suffix/postfix operators.
Given a Degree class:
data class Degree(val value: Double)
one could define a suffix function like so:
suffix fun Double.deg() = Degree(this)
which could be use as follows:
val angle = 90.0 deg
which would get compiled down the equivlant code:
val angle = Degree(90.0)
This is similar to the user-defined literals in C++11.