what am I missing?

# announcements

[Michael de Kaste]

what am I missing?

[Michael de Kaste]

ProductImpl is a data class that contains a

val code: String
val description: String?

so why can't I delegate?

[streetsofboston]

Maybe the getValue(…) is an extension function on KProperty0, and you’d need to import that getValue extension function….?

[Michael de Kaste]

nope, we dont have extension functions on KProperty in our project

[streetsofboston]

I mean, the kotlin stdlib has these extension functions and you’d need to import them…

[Michael de Kaste]

never needed to do that and I cannot find them either way

[streetsofboston]

Hmmmm… you’re correct, you should not need to explicitly import them. The getValue extension function is defined in the the kotlin.reflect package, in the PropertyReferenceDelegates.kt file in the kotlin-stdlib-common library…

[streetsofboston]

(I checked on Kotlin 1.4.10….)

[Vampire]

It works fine with 1.4.10, but it fails on 1.3.72

[Vampire]

https://play.kotlinlang.org/#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

[streetsofboston]

IIRC, the fact that you can use a KProperty as a delegate is new in Kotlin 1.4

[Michael de Kaste]

interesting, we are indeed still on 1.3

[Michael de Kaste]

We wanted to upgrade our project to 1.4.10 anyways so I'll check if it'll break our project

[Michael de Kaste]

otherwise thanks

[streetsofboston]

Yup, only since 1.4 https://kotlinlang.org/docs/reference/delegated-properties.html#delegating-to-another-property

[Tobias Berger]

or you could just use a normal getter, which is easier to understand for newcomers and doesn't need reflection

override val code get() = product.code