How to check whether generic parameter T is nullable?

Question

Given a function

inline fun <reified T> foo() {
    //... do something differently if T is nullable ...
}

how do I check whether T is nullable or not?

Answer 1

Sounds so obvious, once you know it:

T is nullable... if null can be of type T .

eg

inline fun <reified T> isTypeNullable(): Boolean = when {
    null is T -> true
    else -> false
}

cf. https://ideone.com/Pz3ia6

(Important, here, that T is reified , otherwise it will be erased and the whole thing throws an exception)