1. Create a new Qt Widgets Application project.
2. Open the project's file main.cpp:

   #include "mainwindow.h"
   #include <QApplication>
   
   int main(int argc, char *argv[])
   {
       QApplication a(argc, argv);
       MainWindow w;
       w.show();
   
       return a.exec();
   }
   

3. Fold function main:
   

When main is folded, the return and the closing brace should not be shown. Creator 3.0 does this right.