18    using time = std::chrono::high_resolution_clock::time_point;
 
   19    using duration = std::chrono::duration<double>;
 
   20    bool m_has_started = 
false, m_has_stopped = 
false;
 
   21    time m_starting_clock;
 
   23    duration m_cumulative = duration(0);
 
   25    [[nodiscard]] duration as_duration() 
const;
 
   27    enum Unit { Seconds, Milliseconds, Microseconds };
 
   44    [[nodiscard]] 
double count(Unit t_unit = Seconds) 
const;
 
   53    [[nodiscard]] 
double factor(Unit t_unit) 
const;