Get elapsed time in Qt

I think it’s probably better to use QElapsedTimer since that is why the class exists in the first place. It was introduced with Qt 4.7. Note that it is also immuned to system’s clock time change.

Example usage:

#include <QDebug>
#include <QElapsedTimer>
...
...
QElapsedTimer timer;
timer.start();
slowOperation();  // we want to measure the time of this slowOperation()
qDebug() << timer.elapsed();