redef fun enlarge(cap)
	do
		var c = capacity
		if cap <= c then return
		if c <= 16 then c = 16
		while c <= cap do c = c * 2
		# The COW flag can be set at false here, since
		# it does a copy of the current `Buffer`
		written = false
		var bln = _byte_length
		var a = new CString(c)
		if bln > 0 then
			var it = _items
			if bln > 0 then it.copy_to(a, bln, 0, 0)
		end
		_items = a
		capacity = c
	end