message: Specify bits must be 16 elements long
diff: /// Given an array containing the number of codes of each code length,
  /// this function generates the huffman codes lengths and their respective
  /// code lengths as specified by the JPEG spec.
  -fn derive_codes_and_sizes(bits: &[u8]) -> ([u8; 256], [u16; 256]) {
  +fn derive_codes_and_sizes(bits: &[u8; 16]) -> ([u8; 256], [u16; 256]) {
  let mut huffsize = [0u8; 256];
  let mut huffcode = [0u16; 256];
  @@ -48,7 +48,7 @@ fn derive_codes_and_sizes(bits: &[u8]) -> ([u8; 256], [u16; 256]) {
  (huffsize, huffcode)
  }
  -pub(crate) fn build_huff_lut(bits: &[u8], huffval: &[u8]) -> [(u8, u16); 256] {
  +pub(crate) fn build_huff_lut(bits: &[u8; 16], huffval: &[u8]) -> [(u8, u16); 256] {
  let mut lut = [(17u8, 0u16); 256];
  let (huffsize, huffcode) = derive_codes_and_sizes(bits);
  