Hello I've started to use Qt Designer 5.14

In the Designer, I created a simple main window with one button. I run uic.exe to generate a C++ header for it.

To show the window I do:

QMainWindow w;
Ui::MainWindow mw; //The uic generated mainwindow class
mw.setupUi(&w);
w.show();

So far so good.

Now comes the part I don't understand
I want the button to generate a signal that I can handle in C++ code.

So in Designer I added a new slot to the mainwindow called do_something()
And then in the Signal/Slot editor added Sender: pushButton Signal: clicked() Receiver: mainwindow Slot: do_something()

This, I thought, would generate a do_something() method in the generated Ui::MainWindow class header by uic, so I could then implement the method and add what should happen when the button is pushed.

But the only thing that gets generated is:
QObject::connect(pushButton, SIGNAL(clicked()), MainWindow, SLOT(do_something()));

I do not understand where I should implement do_something() so I can make stuff happen when the button is pushed.

I may have missunderstood how Qt Works...

Thanks for any help!