parcelable_on_diet__creator.kt

inline fun <reified T : Parcelable> Parcel.readParcelable(): T? {
    val exists = readInt() == 1
    if (!exists) return null
    return parcelableCreator<T>().createFromParcel(this)
}

@Suppress("UNCHECKED_CAST")
inline fun <reified T : Parcelable> parcelableCreator(): Parcelable.Creator<T> =
    T::class.java.getDeclaredField("CREATOR").get(null) as? Parcelable.Creator<T>
        ?: throw IllegalArgumentException("Could not access CREATOR field in class ${T::class.simpleName}")

fun <T : Parcelable> Parcel.writeParcelable(t: T?) {
    if (t == null) {
        writeInt(0)
    } else {
        writeInt(1)
        t.writeToParcel(this, 0)
    }
}