kotlin-fork/compiler/testData/diagnostics/tests/smartCasts/incDecToNull.kt

// FIR_IDENTICAL
class IncDec {
    <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun inc(): Unit {}
}

fun foo(): IncDec {
    var x = IncDec()
    x = x<!INC_DEC_SHOULD_NOT_RETURN_UNIT!>++<!>
    x<!INC_DEC_SHOULD_NOT_RETURN_UNIT!>++<!>
    return x
}