publish sevomoteur angle

edit

hi, i created a program that published angle of servomotor, and also this code to subscribe to this angle:

    #include "ros/ros.h"
#include "std_msgs/Uint16.h"
int angle = 0;
void angleCallback(const std_msgs::String::ConstPtr& servo_msg)
{
Angle = servo_msg->angle
ROS_INFO("I turn: [%d]degree", angle
}
int main(int argc, char **argv)
{
ros::init(argc, argv, "angle_listener");
ros::NodeHandle n;
ros::Subscriber sub = n.subscribe("/servo", 1000, angleCallback);
ros::spin();
return 0;
}

but i have an error in my code in fonction angleCallback. Can you help me please?