Registering a callback in C++ from a joystick device library - c++

Question

I found a library to handle joystick USB devices in C++ in
simple cross-platform gamepad library so I am trying to attach the callbacks from it to my application. So it has the following definitions
struct Gamepad_device {
unsigned int deviceID;
const char * description;
int vendorID;
int productID;
unsigned int numAxes;
unsigned int numButtons;
float * axisStates;
bool * buttonStates;
void * privateData;
};
[...]
/* Registers a function to be called whenever a device is attached. The specified
function will be called only during calls to Gamepad_init() and
Gamepad_detectDevices(), in the thread from which those functions were called.
Calling this function with a NULL argument will stop any previously registered
callback from being called subsequently. */
void Gamepad_deviceAttachFunc
(void (* callback)
(struct Gamepad_device * device, void * context), void * context);
Thus I am trying to attach this function Gamepad_deviceAttachFunc to a private function in my application.
I tried to register my private function joystickIsAttached (Gamepad_device device) using
Gamepad_deviceAttachFunc(joystickIsAttached(*Gamepad_device));
and
Gamepad_deviceAttachFunc(joystickIsAttached(*Gamepad_device));
but both lead me to
error: expected primary-expression before ')' token
Gamepad_deviceAttachFunc(joystickIsAttached(*Gamepad_device));
or
error: expected primary-expression before ')' token
Gamepad_deviceAttachFunc(joystickIsAttached(Gamepad_device));
Update
I also tried to define the called function as
void joystickDeviceAttachedCallback
(struct Gamepad_device * device, void * context);
and register the callback using
Gamepad_deviceAttachFunc(joystickDeviceAttachedCallback, (void *) 0x1);
but this leads to
error: cannot convert 'MainWindow::joystickDeviceAttachedCallback'
from type 'void (MainWindow::)(Gamepad_device*, void*)' to type 'void
()(Gamepad_device, void*)'
Gamepad_deviceAttachFunc(joystickDeviceAttachedCallback, (void *) 0x1);
Thus what did I do wrong (and how can I fix it?)?
Thanks.