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kotlinlang

Why is the `crossinline` keyword required ? Is it a real language feature, or rather a technical limitation of the compiler ?

it’s to be explicit, that this lambda cannot be inlined by itself (in most cases because you pass it to some other non-online function)

without this it may case cases when you think that lambda is inlined (because function is), but it’s not true, because instance still required

It is also used to indicate that  returns from the lambda will be invalid