Qt 5.10 released(blog.qt.io)

    class MyWidget : public QWidget {
       QFormLayout lay;
       QPushButton button;
       QLineEdit edit;

     public:
       MyWidget(QWidget* parent)
         : QWidget{parent}
         , lay{this}
       {
         button.setText("Hello world");
         lay.addRow("Button", &button);
         lay.addRow("Some text", &edit);
       }
    };

    auto my_widg_ptr = std::make_unique<MyWidget>();
    auto my_widg = my_widg_ptr.get();
    
    parent_layout->addWidget(std::move(my_widg_ptr));
    connect(whatever, &foo::bar, 
            [=] { my_widg->do_stuff(); });

    auto my_widg = new MyWidget;
    
    parent_layout->addWidget(my_widg);
    connect(whatever, &foo::bar, 
            [=] { my_widg->do_stuff(); });

    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);