9using Clock = std::chrono::high_resolution_clock;
10using TPoint= std::chrono::time_point<Clock>;
46 using Unit = std::chrono::seconds;
47 using FpSeconds = std::chrono::duration<double, Unit::period>;
48 auto t_e = Clock::now();
double toc(TPoint const &t_b=MyStopWatch.top())
std::chrono::time_point< Clock > TPoint
std::chrono::high_resolution_clock Clock
std::stack< TPoint > MyStopWatch
starting time of stopwatch