qt which already has a layout

If you're asking about Qt framework, then "which already has a layout" could mean different things depending on the context.

If you're referring to the fact that Qt widgets have a layout system, then yes, it's true. Qt provides a set of layout classes (such as QHBoxLayout, QVBoxLayout, QGridLayout, etc.) that make it easy to arrange widgets in your application's user interface.

If you're asking whether a specific Qt widget already has a layout set up by default, then it depends on the widget. Some widgets, such as QDialog or QMainWindow, have a default layout set up for you. Other widgets, like QPushButton or QLabel, don't have a layout by default, but you can add one yourself if needed.

In any case, if you need to modify the layout of a widget, you can always access and modify its layout through the widget's "layout" property (e.g. widget->layout()).