Enum DataType

include/thundersvm/util/log.h:3445–3447

    class PerformanceTrackingData {
 public:
  enum class DataType : base::type::EnumType {
    Checkpoint = 1, Complete = 2
  };
  // Do not use constructor, will run into multiple definition error, use init(PerformanceTracker*)
  explicit PerformanceTrackingData(DataType dataType) : m_performanceTracker(nullptr),
    m_dataType(dataType), m_firstCheckpoint(false), m_file(""), m_line(0), m_func("") {}