message: change auto to size_type in dense matrix conversion
diff: @@ -219,7 +219,7 @@ void convert_to_coo(std::shared_ptr<const OmpExecutor> exec,
  auto col_idxs = result->get_col_idxs();
  auto values = result->get_values();
  - auto idxs = 0;
  + size_type idxs = 0;
  for (size_type row = 0; row < num_rows; ++row) {
  #pragma omp parallel for
  for (size_type col = 0; col < num_cols; ++col) {
  