Call Widget and function from Another .cpp file

// main.cpp

  QApplication a(argc, argv); 
  Card_Creater w;                                                                   
  mfp_set_card_creator(&w); 


// mf.cpp

Card_Creater *m_cardCreator;

 mfp_set_card_creator(Card_Creater *p)

 {

     m_cardCreator = p;

 }

Then we call  from main.cpp within function to mf.cpp 

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