final: prev:
let
  filesystem = fsType: path: device: options: {
    fileSystems.${path} =
      { inherit device fsType; }
      // final.optionalAttrs (options != null) { inherit options; };
  };

in {
  btrfs = filesystem "btrfs";
  ntfs = filesystem "ntfs-3g";
  ext4 = filesystem "ext4";
  vfat = filesystem "vfat";
  zfs = filesystem "zfs";
  tmpfs = filesystem "tmpfs";

  swap = device: {swapDevices = [{inherit device;}];};

  luks = mapper: device: additional: {
    boot.initrd.luks.devices.${mapper} = {
      inherit device;
    } // additional;
  };
}