# Remove `item` at `index`
	fun remove_at(item: E, index: Int)
	do
		var i = index
		length -= 1
		items[i] = null

		var ii = 0
		for s in starts, e in ends do
			if s <= i and i < e then
				if s == e-1 then
					# single item chunk
					starts.remove_at ii
					ends.remove_at ii

					if starts.is_empty then
						items.clear
						available.clear
						return
					end
				else if e-1 == i then
					# last item of chunk
					ends[ii] -= 1

				else if s == i then
					# first item of chunk
					starts[ii] += 1
				else
					# break up chunk
					ends.insert(ends[ii], ii+1)
					ends[ii] = i
					starts.insert(i+1, ii+1)
				end

				available.add i
				return
			end
			ii += 1
		end

		abort
	end