Port Kotlin's awesome filterIsInstance() to RxJava — one call to filter by type and map-cast to that type

RxFilterIsInstance.kt

package me.seebrock3r.extensions.reactivex

import io.reactivex.Flowable
import io.reactivex.Maybe
import io.reactivex.Observable
import io.reactivex.Single

@Suppress("UNCHECKED_CAST") // The cast happens after we filter by type so it's safe
inline fun <reified R> Flowable<*>.filterIsInstance(): Flowable<R> =
    filter { it is R }

@Suppress("UNCHECKED_CAST") // The cast happens after we filter by type so it's safe
inline fun <reified R> Observable<*>.filterIsInstance(): Observable<R> =
    filter { it is R }

@Suppress("UNCHECKED_CAST") // The cast happens after we filter by type so it's safe
inline fun <reified R> Single<*>.filterIsInstance(): Maybe<R> =
    filter { it is R }

@Suppress("UNCHECKED_CAST") // The cast happens after we filter by type so it's safe
inline fun <reified R> Maybe<*>.filterIsInstance(): Maybe<R> =
    filter { it is R }