Passing pointers to member function as returned values to QObject::connect()

For design reasons, I need to come up with a way to call QObject::connect() where the function pointers are passed in as returned values of function calls. Namely, instead of using the vanilla syntaxconnect(sender, &Sender::valueChanged, receiver, &Receiver::updateValue);, I have to do something like the following:

//in main.cpp
SENDER *sender = new SENDER;
RECEIVER *receiver = new RECEIVER;
connect(sender, sender->get_func(), receiver, receiver->get_func() );

where SENDER and RECEIVER are defined as follows:

//sender.h
#include <QWidget>

class SENDER : public QWidget{

  Q_OBJECT
  public:
    void(* get_func() ) (double, double);

  signals:
    void send_data(double x, double y);

};

//sig_sender.cpp
#include "sender.h"

void (* SENDER::get_func() )(double, double)
{
    return send_data;
}

//sig_receiver.h
#include <QWidget>

class RECEIVER : public QWidget{

  Q_OBJECT
  public:
    void receive_data(double x, double y);
    void(* get_func() ) (double, double);

};

//sig_receiver.cpp
#include "receiver.h"

void (* RECEIVER::get_func() )(double, double)
{
    return receive_data;
}

Attempts to compile give me the following error:

/home/abc/work/mainwindow.cpp:14: error: no matching function for call to ‘MainWindow::connect(SENDER*&, void (*)(double, double), RECEIVER*&, void (*)(double, double))’
     connect(sender, sender->get_func(), receiver, receiver->get_func() );

What am I doing wrong here?