{

Stopwatch()

: in_use_(false)

{}

inline void Start()

{

in_use_ = true;

start_time_ = std::chrono::steady_clock::now();

}

inline double Stop()

{

stop_time_ = std::chrono::steady_clock::now();

in_use_ = false;

return time();

}

inline bool in_use() const

{

return in_use_;

}

inline double time() const

{

const auto duration = stop_time_ - start_time_;

return std::chrono::duration<double,std::nano>(duration).count();

}

typedef std::chrono::time_point<std::chrono::steady_clock> time_point_t;

time_point_t start_time_;

time_point_t stop_time_;

bool in_use_;