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kotlinlang

<@U0CD3CDM4> what version of kotlin and IDEA you use? It works fine

Did you try uncommenting the line `//  println(foo().reversed())`? Does it still work?

yes, it works. what version of kotlin you use? in my case it 1.2.41

Huh, works for me, but Kotlin plugin 1.2.40 complains about this case

I have the issue with kotlin 1.2.41 and Intellij 2018.1

ah, it works if I wrap the example in a class and function

Yeah, same for me, still kinda strange that it doesn’t work for top level code (for example in kts or scratch file

I’ve narrowed it down further. If the `val` is a property in a class then I get the error, if it is a local variable in a function then it works

Yup, can confirm the same:
```
open class ClassA&lt;T&gt; {
    open operator fun invoke(): T? = null
}

class ClassB&lt;T : Any&gt;(private val value: T) : ClassA&lt;T&gt;() {
    override operator fun invoke(): T = value
}

class OtherClass {
    private val foo: ClassA&lt;String&gt; = ClassB("123")

    init {
        if (foo is ClassB) {
            // This smart casts to String
            println(foo.invoke().reversed())
            // This doesn't and is still String?
            println(foo().reversed())
        }
    }
}
```
If I move foo inside of `init` then it fails

it is very interesting
```
open class ClassA&lt;T&gt; {
    open operator fun invoke(): T? = null
}

class ClassB&lt;T : Any&gt;(private val value: T) : ClassA&lt;T&gt;() {
    override operator fun invoke(): T = value
}

class Test {
    val foo: ClassA&lt;String&gt; = ClassB("123")

    init {
        if (foo is ClassB) {
            // This smart casts to String
            println(foo.invoke().reversed())
            // This doesn't and is still String?
            println(foo().reversed())
            // works!
            println((foo)().reversed())
        }
    }
    @Test
    fun test() {

        if (foo is ClassB) {
            // This smart casts to String
            println(foo.invoke().reversed())
            // This doesn't and is still String?
            println(foo().reversed())
            // works!
            println((foo)().reversed())
        }
        val foo: ClassA&lt;String&gt; = ClassB("123")


        if (foo is ClassB) {
            // This smart casts to String
            println(foo.invoke().reversed())
            // works!
            println(foo().reversed())
            // works!
            println((foo)().reversed())
        }
    }
}
```

very strange
```
            // This doesn't and is still String?
            println(foo().reversed())
            // works!
            println((foo)().reversed())
```

I have an example in our app in which that doesn't fix it either. If I do `(foo as Success))()`then it works even though it is already in an `if (is Success)` block.

Kotlin then warns about a useless cast which I have to suppress

you can omit cast, but do not remove brackets - this is a bug

Filed <https://youtrack.jetbrains.com/issue/KT-24454>

<@U0CD3CDM4> I mean that cast in `(foo as Success)()` is needless, sufficiently round brackets `(foo)()` needed for workaround bug