title: Qt UI for existing C++ project
body: <p>I have already written a C++ program and I would like to write a GUI for it. I realize Qt is a wonderful tool, however, Qt has it's own classes, which make me quite confused. eg: instead of String, Qt has a class named QString..</p>
  
  <p>I am wondering if I can mix C++ code and Qt code in C++? </p>