Correct way to quit a Qt program?

Question

How should I quit a Qt Program, e.g when loading a data file, and discovered file corruption, and user need to quit this app or re-initiate data file?

Should I:

Answer 1

While searching this very question I discovered this example in the documentation.

QPushButton *quitButton = new QPushButton("Quit");
connect(quitButton, &QPushButton::clicked, &app, &QCoreApplication::quit, Qt::QueuedConnection);

Mutatis mutandis for your particular action of course.

Along with this note.

It's good practice to always connect signals to this slot using a QueuedConnection. If a signal connected (non-queued) to this slot is emitted before control enters the main event loop (such as before "int main" calls exec()), the slot has no effect and the application never exits. Using a queued connection ensures that the slot will not be invoked until after control enters the main event loop.

It's common to connect the QGuiApplication::lastWindowClosed() signal to quit()