The easy way would be to create new functions for each of the primitives (one each for

property(value: Primitive)

,

property(block: () -> PrimitiveProperty)

, and

Any.getProperty(prop: KMutableProperty<*, Primitive>)

(that's 15 new functions; I missed

Any.getProperty

earlier)) and new classes for each primitive delegate (

PrimitivePropertyDelegate

(5 new classes)), but that's a lot of new code to maintain.