#include <QApplication>

#include <QHBoxLayout>
#include <QPushButton>
#include <QMainWindow>

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

QMainWindow *window = new QMainWindow;
 window->setLayoutDirection( Qt::LeftToRight ); // This line shouldn't make a difference
 QWidget *widget = new QWidget;
 QPushButton *button1 = new QPushButton("One");
 QPushButton *button2 = new QPushButton("Two");
 QPushButton *button3 = new QPushButton("Three");
 QPushButton *button4 = new QPushButton("Four");
 QPushButton *button5 = new QPushButton("Five");

QHBoxLayout *layout = new QHBoxLayout;
 layout->addWidget(button1);
 layout->addWidget(button2);
 layout->addWidget(button3);
 layout->addWidget(button4);
 layout->addWidget(button5);

widget->setLayout(layout);
 window->setCentralWidget(widget);
 window->show();

return a.exec();
}