kotlin-fork/compiler/testData/diagnostics/tests/cast/IsErasedUpcastToNonReified.fir.kt

fun <T, S : T> test(x: T?, y: S, z: T) {
    x is T
    x is T?

    y is T
    y is S
    y is T?
    y is S?

    z is T
    z is T?

    null as T
    null as T?
    null as S
}

inline fun <reified T> test(x: T?) {
    x is T
    null as T
    null as T?
}

fun <T> foo(x: List<T>, y: List<T>?) {
    x is List<T>
    y is List<T>
}