purge functions that returns mutable vector (#136)

modules/planning/common/obstacle.cc

@@ -67,9 +67,5 @@ void Obstacle::add_prediction_trajectory(
   prediction_trajectories_.push_back(prediction_trajectory);
 }
 
-std::vector<PredictionTrajectory>* Obstacle::mutable_prediction_trajectories() {
-  return &prediction_trajectories_;
-}
-
 }  // namespace planning
 }  // namespace apollo

modules/planning/common/obstacle.h

@@ -71,7 +71,6 @@ class Obstacle : public PlanningObject {
   const std::vector<PredictionTrajectory> &prediction_trajectories() const;
   void add_prediction_trajectory(
       const PredictionTrajectory &prediction_trajectory);
-  std::vector<PredictionTrajectory> *mutable_prediction_trajectories();
 
  private:
   std::string id_ = 0;

modules/planning/math/spiral_curve/cubic_spiral_curve.cc

@@ -174,7 +174,7 @@ bool CubicSpiralCurve::calculate_path() {
     ds = sg / (spiral_config().simpson_size() - 1);
   }
 
-  std::copy(p_shoot.begin(), p_shoot.end(), (*mutable_p_params()).begin());
+  prepend_to_p_params(p_shoot.begin(), p_shoot.end());
   set_sg(sg);
   set_error(diff);
 

modules/planning/math/spiral_curve/quintic_spiral_curve.cc

@@ -185,7 +185,7 @@ bool QuinticSpiralCurve::calculate_path() {
   }
 
   // update params
-  std::copy(p_shoot.begin(), p_shoot.end(), (*mutable_p_params()).begin());
+  prepend_to_p_params(p_shoot.begin(), p_shoot.end());
   set_sg(sg);
   set_error(diff);
 

modules/planning/math/spiral_curve/spiral_curve.cc

@@ -57,8 +57,6 @@ const SpiralCurveConfig& SpiralCurve::spiral_config() const {
   return spiral_config_;
 }
 
-std::vector<double>* SpiralCurve::mutable_p_params() { return &p_params_; }
-
 void SpiralCurve::set_sg(const double sg) { sg_ = sg; }
 
 void SpiralCurve::set_error(const double error) { error_ = error; }

modules/planning/math/spiral_curve/spiral_curve.h

@@ -84,10 +84,13 @@ class SpiralCurve {
   SpiralCurveConfig spiral_config_;
 
  protected:
-  std::vector<double>* mutable_p_params();
   void set_sg(const double sg);
   void set_error(const double error);
   bool result_sanity_check() const;
+  template <typename T>
+  void prepend_to_p_params(T begin, T end) {
+    std::copy(begin, end, p_params_.begin());
+  }
   static constexpr double s_two_pi_ = 2 * M_PI;
 };