Background:

I had a great callback function in a Gazebo plugin. I declared it with

void OnMsg(ConstVector3dPtr &msg)

and subscribed-to by my plugin's Load function with

subscriber = node->Subscribe("~/eb/vel_cmd", &MyPlugin::OnMsg, this);

Problem:

Instead of subscribing to "~/eb/velcmd", I'm subscribing to "/tf", so I need to change the message type of the callback (MyPlugin::OnMsg) to tf2msgs::TFMessage. I followed the convention of the question in the link below to create a constant pointer for a tf2_msgs::TFMessage message.

http://answers.ros.org/question/214814/subscribing-to-ros-and-gazebo-topic-in-one-node-ros-callback-failing/

Following the positionCb callback declaration in that code, now my callback is declared with:

private: void OnMsg(const tf2_msgs::TFMessage::ConstPtr& &msg)

I'm getting all kinds of compiling errors, but the biggest problem appears to be "Cannot declare reference to tf2msgs::TFMessagestd::allocator<void >::ConstPtr& {aka class boost::sharedptr<const tf2msgs::TFMessage_std::allocator<void>&}' (picture below).

Any ideas on what I'm doing incorrectly?

Compiling Errors: