Make print() const

include/gnss/processor/processor_gnss_fix.h

@@ -28,7 +28,7 @@ struct ProcessorParamsGnssFix : public ProcessorParamsBase
         dist_traveled           = _server.getParam<Scalar>(_unique_name + "/dist_traveled");
         enu_map_init_dist_min   = _server.getParam<Scalar>(_unique_name + "/enu_map_init_dist_min");
     }
-    std::string print()
+    std::string print() const
     {
         return "\n" + ProcessorParamsBase::print()                              + "\n"
             + "time_th: "               + std::to_string(time_th)               + "\n"

include/gnss/processor/processor_gnss_single_diff.h

@@ -28,7 +28,7 @@ struct ProcessorParamsGnssSingleDiff : public ProcessorParamsBase
         dist_traveled           = _server.getParam<Scalar>(_unique_name + "/dist_traveled");
         enu_map_init_dist_min   = _server.getParam<Scalar>(_unique_name + "/enu_map_init_dist_min");
     }
-    std::string print()
+    std::string print() const
     {
         return "\n" + ProcessorParamsBase::print()                              + "\n"
             + "time_th: "               + std::to_string(time_th)               + "\n"

include/gnss/sensor/sensor_gnss.h

@@ -30,7 +30,7 @@ struct IntrinsicsGnss : public IntrinsicsBase
             yaw_fixed_          = _server.getParam<bool>(_unique_name + "/yaw_fixed");
             translation_fixed_  = _server.getParam<bool>(_unique_name + "/translation_fixed");
         }
-        std::string print()
+        std::string print() const
         {
             return "\n" + IntrinsicsBase::print()                           + "\n"
             + "extrinsics_fixed: "  + std::to_string(extrinsics_fixed_)     + "\n"