class Foo(val l: Long) : Comparable<Foo> {
    override fun compareTo(other: Foo): Int {
        return l.compareTo(other.l)
    }
}

class Bar(val l: Int) : Comparable<Bar> {
    override fun compareTo(other: Bar): Int {
        return l.compareTo(other.l)
    }
}

operator fun <TLhs : Any, TRhs : Any> TLhs.compareTo(rhs: TRhs): Int = (this as Comparable<TLhs>).compareTo(rhs as TLhs)

infix fun Any?.isGreaterThan(expected: Any?): Boolean {
    if (this == null) return false
    if (expected == null) return false
    return this > expected
}

fun main(args: Array<String>) {
    val aFoo = Foo(1L)
    val aBar = Bar(1)
    println(aFoo isGreaterThan aBar)
}

// On JVM:
//  Exception in thread "main" java.lang.ClassCastException: Bar cannot be cast to Foo
//  at Foo.compareTo(main.kt:1)
//  at MainKt.compareTo(main.kt:13)
//  at MainKt.isGreaterThan(main.kt:18)
//  at MainKt.main(main.kt:24)
//  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
//  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
//  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
//  at java.lang.reflect.Method.invoke(Method.java:498)
//  at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)

// On JS
// Uncaught TypeError: other.isNegative is not a function kotlin.js:2258
// which is var otherNeg = other.isNegative(); in Kotlin.Long.compareTo