How to remove the default menu on the left side of the title bar - Qt?

[TheIndependentAquarius]

Qt :: WindowFlags flags = 0;
 
    // Makes the Pomodoro stay on the top of all windows.
    flags |= Qt :: WindowStaysOnTopHint;
 
    // Removes minimize, maximize, and close buttons.
    flags |= Qt :: WindowTitleHint | Qt :: CustomizeWindowHint;
 
    window->setWindowFlags (flags);
    window->setWindowTitle ("Failing to plan is planning to fail");

Qt :: WindowFlags flags = 0;

    // Makes the Pomodoro stay on the top of all windows.
    flags |= Qt :: WindowStaysOnTopHint;

    // Removes minimize, maximize, and close buttons.
    flags |= Qt :: WindowTitleHint | Qt :: CustomizeWindowHint;

    window->setWindowFlags (flags);
    window->setWindowTitle ("Failing to plan is planning to fail");

To copy to clipboard, switch view to plain text mode 

This removes minimize, maximize, and close buttons. The default menu on the left is still there. How to get rid of that?

I want the title bar to be there, but just want the menu to be removed.

Default menu contains: Minimize, Maximize, Move etc options.

[Spitfire]

On what system?

this->setWindowFlags( Qt :: WindowStaysOnTopHint | Qt::WindowTitleHint | Qt::CustomizeWindowHint );

this->setWindowFlags( Qt :: WindowStaysOnTopHint | Qt::WindowTitleHint | Qt::CustomizeWindowHint );

To copy to clipboard, switch view to plain text mode 

works as you want on W7 and Ubuntu.