text: // Copyright (C) 2020  I. Bogoslavskyi, C. Stachniss
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the "Software"),
  // to deal in the Software without restriction, including without limitation
  // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  // and/or sell copies of the Software, and to permit persons to whom the
  // Software is furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in
  // all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  // DEALINGS IN THE SOFTWARE.
  
  #ifndef SRC_UTILS_TIMER_H_
  #define SRC_UTILS_TIMER_H_
  
  #include <chrono>
  
  namespace depth_clustering {
  
  namespace time_utils {
  
  using MicroSecs = std::chrono::microseconds;
  using MilliSecs = std::chrono::milliseconds;
  using Clock = std::chrono::high_resolution_clock;
  using TimePoint = std::chrono::time_point<Clock>;
  using std::chrono::duration_cast;
  
  /**
   * @brief      A small utility time measurement class
   */
  class Timer {
   public:
    enum class Units { Micro, Milli };
    void start() { _start = Clock::now(); }
    uint64_t measure(const Units& units = Units::Micro) {
      auto end = Clock::now();
      uint64_t res = 0;
      switch (units) {
        case Units::Micro:
          res = duration_cast<MicroSecs>(end - _start).count();
          break;
        case Units::Milli:
          res = duration_cast<MilliSecs>(end - _start).count();
          break;
      }
      _start = Clock::now();
      return res;
    }
  
   private:
    TimePoint _start = Clock::now();
  };
  
  }  // namespace time_utils
  
  }  // namespace depth_clustering
  
  #endif  // SRC_UTILS_TIMER_H_
  