migrate: Qt5/C++11 app to Qt6/C++23 with tests and modern Qt APIs

Entire-Checkpoint: c1ee98dc34a3

qt6-after/qt6-migrated-benchmark/MainWindow.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <QMainWindow>
+#include <QRegularExpression>
+#include <QString>
+
+QT_BEGIN_NAMESPACE
+
+namespace Ui
+{
+class MainWindow;
+}
+
+QT_END_NAMESPACE
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+  public:
+    explicit MainWindow(QWidget* parent = nullptr);
+    ~MainWindow() override;
+
+  private slots:
+    void onValidateClicked();
+    void onScreenInfoClicked();
+
+  private:
+    Ui::MainWindow* ui;
+    QRegularExpression pattern;
+};