object pointer as ROS message

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Is it possible to pass an object pointer as a ROS message? Below a MWE, that doesn't even get to compile with error message:

talker.cpp:20:12: error: invalid conversion from ‘Foo*’ to ‘std_msgs::UInt64_<std::allocator<void> >::_data_type {aka long unsigned int}’ [-fpermissive]
msg.data = &foo;
         ^

MWE:

#include <iostream>
#include "ros/ros.h"
#include "std_msgs/UInt64.h"

class Foo
{
   public:
      int count;
};

int main(int argc, char **argv)
{
  ros::init(argc, argv, "talker");
  ros::NodeHandle n;
  ros::Publisher chatter_pub = n.advertise<std_msgs::UInt64>("chatter", 1000);
  ros::Rate loop_rate(10);
  Foo foo;
  foo.count = 0;
  std_msgs::UInt64 msg;
  msg.data = &foo;
  while (ros::ok())
  {
    chatter_pub.publish(msg);
    ros::spinOnce();
    loop_rate.sleep();
    ++foo.count;
  }
  return 0;
}

Might be a silly question give that the pointer is of the object type pointer, but all I need to do is pass the integer hex memory address to another node (and hopefully create a same object pointer that points to the same address). Possibly, a dangerous thing to do but it will suffice. Any help appreciated.