Example C++ Subscription, use `c++ -I/opt/ros/hydro/include -L/opt/ros/hydro/lib -lroscpp -lroscpp_serialization -lrosconsole my_node.cpp -o my_node`

my_node.cpp

#include <vector>

#include "ros/ros.h"
#include "geometry_msgs/PoseStamped.h"

std::vector<geometry_msgs::PoseStamped::ConstPtr> poses;

void handle_poses(const geometry_msgs::PoseStamped::ConstPtr& msg)
{
  ROS_INFO_STREAM("Received pose: " << msg);
  // Use the msg object here to access the pose elements,
  // like msg->pose.pose.position.x
  poses.push_back(msg);
}

int main(int argc, char **argv)
{
  ros::init(argc, argv, "my_node");

  ros::NodeHandle n;

  ros::Subscriber sub = n.subscribe("/monocular_pose_estimator/estimated_pose",
    1000, handle_poses);

  ros::spin();

  return 0;
}