qrect marginsadded C++ code

Here's an example of how to use the `marginsAdded` signal of a `QRect` in C++:

#include <QApplication>
#include <QRect>
#include <QDebug>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QRect rect(10, 10, 50, 50);
    QObject::connect(&rect, &QRect::marginsAdded, [](int left, int top, int right, int bottom) {
        qDebug() << "Margins added: Left =" << left << "Top =" << top << "Right =" << right << "Bottom =" << bottom;
    });

    rect.adjust(5, 5, 5, 5);

    return app.exec();
}

In this example, we create a `QRect` object with coordinates (10, 10) and size 50x50. Then, we connect the `marginsAdded` signal of the rectangle to a lambda function that will be called every time the rectangle's margins are adjusted. We use the `adjust()` function to add a 5-pixel margin to all sides of the rectangle, which will trigger the `marginsAdded` signal and print the new margins to the console.