how would I write

as?

as a function?

foo.tryAs(String)

=

foo as? String

inline fun <reified T> Any.tryAs(): T? = this as? T

The angle brackets specify a type parameter. You call it like this.

foo.tryAs<String>()

For more explanation read this section of the docs: https://kotlinlang.org/docs/inline-functions.html#reified-type-parameters

thanks a lot!

you don’t need your own extension, KClass already has a safecast function so

foo::class.safeCast(bar)

(from an instance of foo)