message: index with iter
diff: @@ -238,9 +238,9 @@ fn init_foreign_field_add_rows<F: PrimeField>(
  result_carry: [F; 2],
  upper_bound_carry: [F; 2],
  ) {
  - for (row, _) in WITNESS_SHAPE.iter().enumerate() {
  + for (row, wit) in WITNESS_SHAPE.iter().enumerate() {
  for col in 0..COLUMNS {
  - match &WITNESS_SHAPE[row][col] {
  + match &wit[col] {
  WitnessCell::Standard(standard_cell) => {
  handle_standard_witness_cell(
  witness,
  