```inline fun <T, reified R> Array<T>....

# stdlib

[Hullaballoonatic]

inline fun <T, reified R> Array<T>.mapToArray(transform: (T) -> R) = 
    Array(size) { transform(get(it)) }

etc for List, primitive arrays...

[miha-x64]

The downside is that you need reified R which is not always available in generic library code.
Alternative: https://github.com/Miha-x64/Kotlin-MPP_Collection_utils/blob/master/src/commonMain/kotlin/net/aquadc/collections/arr.kt#L107

[Hullaballoonatic]

cool, thanks