Error when creating a subclass object

Hi,

I am relatively beginner in C++. I have the following question.
I have two classes, CMotionPlanner which is the base class, and CCollisionObject which is the derived / subclass.

Code:

---

class CCollisionObject : public CMotionPlanner
{
public:
  CCollisionObject() : CMotionPlanner()
  {
    m_pubObstaclesPub = m_nh.advertise<moveit_msgs::CollisionObject>("/collision_object", 10);
  }

  void AddObstacle(int choice);

private:
  ros::Publisher m_pubObstaclesPub;
  moveit_msgs::CollisionObject          m_CollisionObject;
  shape_msgs::SolidPrimitive primitive;

};

---

Then, I create an object of the subclass, so that I can invoke class methods. See the code below.

Code:

---

int main(int argc, char* argv[])
{
  ros::init(argc, argv, "ccollisiobobject");

  CCollisionObject co;

  int selection = atoi(argv[1]);
  co.AddObstacle(selection);

  ros::shutdown();

  return 0;
}

---

However, I get errors. The program does not compile. The error is the following.

Code:

---

CMakeFiles/obs_node.dir/src/ccollisionobject.cpp.o: In function `CCollisionObject::CCollisionObject()':
ccollisionobject.cpp:(.text._ZN16CCollisionObjectC2Ev[_ZN16CCollisionObjectC5Ev]+0x24): undefined reference to `CMotionPlanner::CMotionPlanner()'
collect2: error: ld returned 1 exit status

---

The base class constructor looks like this.

Code:

---

CMotionPlanner::CMotionPlanner() :
  m_strPlanningGroup("manipulator"),
  m_MoveGroup(m_strPlanningGroup)
{
  m_SamplePose.orientation.w = 0.0;
  m_SamplePose.position.x = 0.51;
  m_SamplePose.position.y = 0.3;
  m_SamplePose.position.z = 0.8;
}

---

Please, can you help me with this.

thanks,
Zahid

So do you have a cmotionplanner.cpp file?

Are you compiling it?

> undefined reference to
These typically result from
- not compiling all your source code
- not being able to spell correctly.

thanks @salem for pointer in this direction.

I have a CMakeLists.txt file. I wanted to create separate ROS nodes (executable) one based on CMotionPlanner and other based on CCollisionObject. Thus, initially, my CMakeLists.txt looked as follows.

Code:

---

add_executable(motion_node src/main.cpp src/motionplanner.cpp)
add_executable(obs_node src/ccollisionobject.cpp)

## Specify libraries to link a library or executable target against
target_link_libraries(motion_node ${catkin_LIBRARIES})
target_link_libraries(obs_node ${catkin_LIBRARIES})

---

but, when I changed it to

Code:

---

add_executable(motion_node src/main.cpp src/motionplanner.cpp)
add_executable(obs_node src/motionplanner.cpp src/ccollisionobject.cpp)

## Specify libraries to link a library or executable target against
target_link_libraries(motion_node ${catkin_LIBRARIES})
target_link_libraries(obs_node ${catkin_LIBRARIES})

---

it compiles correctly, producing two nodes motion_node, and obs_node.

Do you think, this kind of reasoning has any logical flaws to it.

thanks,
Zahid