joystick_manual_control.h

namespace ros_control_boilerplate
{

class JoystickManualControl
{
public:

  /**
   * \brief Constructor
   * \param parent_name - name of parent class, only used for namespacing logging debug output
   * \param service_namespace - prefix to controller manager service, or blank. do not add trailing "/"
   */
  JoystickManualControl(const std::string& parent_name, const std::string& service_namespace)
     : parent_name_(parent_name)
     , using_trajectory_controller_(true)
  {
    switch_service_ = service_namespace + "/controller_manager/switch_controller";
    load_service_ = service_namespace + "/controller_manager/load_controller";

    // Switch modes of controllers
    switch_controlers_client_ = nh_.serviceClient<controller_manager_msgs::SwitchController>(switch_service_);
    load_controlers_client_ = nh_.serviceClient<controller_manager_msgs::LoadController>(load_service_);

    // Subscribe to joystick control
    std::size_t queue_size = 1;
    remote_joy_ = nh_.subscribe("/joy", queue_size, &JoystickManualControl::joyCallback, this);

    ROS_INFO_STREAM_NAMED(parent_name_,"JoystickManualControl Ready.");
  }

they have called to functions in line 14 , 15 after JoystickManualControl() :foo bar {}.

Is it correct syntex?
What is does?