``` operator fun <T> List<T>.get(index...

# announcements

[winteryoung]

operator fun <T> List<T>.get(index: Int) = this.getx(index)

fun <T> List<T>.getx(index: Int): T {
    val i = xindex(index)
    return this[i]
}

private fun <T> List<T>.xindex(index: Int): Int {
    val i = if (index < 0) {
        this.size + index
    } else {
        index
    }
    return i
}

fun <T> MutableList<T>.setx(index: Int, value: T) {
    this[xindex(index)] = value
}

If define List.get like above, code like list[-1] still won't work