# Sets the buffering mode for the current FileStream
	#
	# If the buf_size is <= 0, its value will be 512 by default
	#
	# The mode is any of the buffer_mode enumeration in `Sys`:
	#
	# * `buffer_mode_full`
	# * `buffer_mode_line`
	# * `buffer_mode_none`
	fun set_buffering_mode(buf_size, mode: Int) do
		if buf_size <= 0 then buf_size = 512
		if _file.as(not null).set_buffering_type(buf_size, mode) != 0 then
			last_error = new IOError("Error while changing buffering type for FileStream, returned error {sys.errno.strerror}")
		end
	end