Kotlin: arrayOfNulls() with generic type

[Ursego]

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by Ursego » 31 Dec 2019, 20:28

If you write

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val arr = arrayOfNulls<T>(5)

you get a compilation error "Cannot use 'T' as reified typealias parameter. Use a class instead.".

Solution: In your "util" package, create the global function genericArrayOfNulls():

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@Suppress("UNCHECKED_CAST")
fun <T> genericArrayOfNulls(size: Int): Array<T?> = arrayOfNulls<Any?>(size) as Array<T?>

Now, you can use it instead of arrayOfNulls():

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val arr = genericArrayOfNulls(5)