gistfile1.cpp

#include <chrono>

struct stop_watch final
{
    stop_watch() : Start_(now()) {}
    
    std::chrono::seconds elapsed_s() const
    {
        using std::chrono::seconds;
        return std::chrono::duration_cast<seconds>(elapsed());
    }
    
    std::chrono::milliseconds elapsed_ms() const
    {
        using std::chrono::milliseconds;
        return std::chrono::duration_cast<milliseconds>(elapsed());
    }
    
    std::chrono::microseconds elapsed_us() const
    {
        using std::chrono::microseconds;
        return std::chrono::duration_cast<microseconds>(elapsed());
    }
    
    std::chrono::nanoseconds elapsed_ns() const
    {
        using std::chrono::nanoseconds;
        return std::chrono::duration_cast<nanoseconds>(elapsed());
    }
    
    void restart() { Start_ = now(); }
    
    stop_watch(const stop_watch&) = delete;
    stop_watch& operator=(const stop_watch&) = delete;
    
private:
    static std::chrono::high_resolution_clock::time_point now()
    {
        return std::chrono::high_resolution_clock::now();
    }
    
    std::chrono::duration<double> elapsed() const
    {
        return now() - Start_;
    }
    
    std::chrono::high_resolution_clock::time_point Start_;
};