Mini C++ profiler (support multicore)

profiler.cpp

struct profiler {
  profiler() : m_start{chrono::high_resolution_clock::now()} {

  }
  size_t til_now() const {
    return chrono::duration_cast<chrono::milliseconds>(
      chrono::high_resolution_clock::now() - m_start).count();
  }

  chrono::high_resolution_clock::time_point m_start;
};