~$ ls -l /home/igor/projects/test/test.cpp 
-rw-rw-r-- 1 igor igor 306 кві 25 09:55 /home/igor/projects/test/test.cpp

   vector<string> v { "123", "456" };
   for( string s : v )
     s.

   vector<string> v { "123", "456" };
   v[ 0 ].

#include <gtk/gtk.h>

static cairo_surface_t *surface = NULL;

static void
clear_surface (void)
{
  cairo_t *cr;

  cr = cairo_create (surface);

  cairo_set_source_rgb (cr, 1, 1, 1);
  cairo_paint (cr);

  cairo_destroy (cr);
}

static gboolean
configure_event_cb (GtkWidget         *widget,
            GdkEventConfigure *event,
            gpointer           data)
{
  if (surface)
    cairo_surface_destroy (surface);

  surface = gdk_window_create_similar_surface (gtk_widget_get_window (widget),
                                       CAIRO_CONTENT_COLOR,
                                       gtk_widget_get_allocated_width (widget),
                                       gtk_widget_get_allocated_height (widget));

  clear_surface ();

  return TRUE;
}

static gboolean
draw_cb (GtkWidget *widget,
 cairo_t   *cr,
 gpointer   data)
{
  cairo_set_source_surface (cr, surface, 0, 0);
  cairo_paint (cr);

  return FALSE;
}

static void
draw_brush (GtkWidget *widget,
    gdouble    x,
    gdouble    y)
{
  cairo_t *cr;

  cr = cairo_create (surface);

  cairo_rectangle (cr, x - 3, y - 3, 6, 6);
  cairo_fill (cr);

  cairo_destroy (cr);

  gtk_widget_queue_draw_area (widget, x - 3, y - 3, 6, 6);
}

static gboolean
button_press_event_cb (GtkWidget      *widget,
               GdkEventButton *event,
               gpointer        data)
{
  if (surface == NULL)
    return FALSE;

  if (event->button == 1)
    {
      draw_brush (widget, event->x, event->y);
    }
  else if (event->button == 3)
    {
      clear_surface ();
      gtk_widget_queue_draw (widget);
    }

  return TRUE;
}

static gboolean
motion_notify_event_cb (GtkWidget      *widget,
                GdkEventMotion *event,
                gpointer        data)
{
  int x, y;
  GdkModifierType state;

  if (surface == NULL)
    return FALSE;

  gdk_window_get_pointer (event->window, &x, &y, &state);

  if (state & GDK_BUTTON1_MASK)
    draw_brush (widget, x, y);

  return TRUE;
}

static void
close_window (void)
{
  if (surface)
    cairo_surface_destroy (surface);

  gtk_main_quit ();
}

int
main (int   argc,
      char *argv[])
{
  GtkWidget *window;
  GtkWidget *frame;
  GtkWidget *da;

  gtk_init (&argc, &argv);

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  gtk_window_set_title (GTK_WINDOW (window), "Drawing Area");

  g_signal_connect (window, "destroy", G_CALLBACK (close_window), NULL);

  gtk_container_set_border_width (GTK_CONTAINER (window), 8);

  frame = gtk_frame_new (NULL);
  gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_IN);
  gtk_container_add (GTK_CONTAINER (window), frame);

  da = gtk_drawing_area_new ();
  gtk_widget_set_size_request (da, 100, 100);

  gtk_container_add (GTK_CONTAINER (frame), da);

  g_signal_connect (da, "draw",
            G_CALLBACK (draw_cb), NULL);
  g_signal_connect (da,"configure-event",
            G_CALLBACK (configure_event_cb), NULL);

  g_signal_connect (da, "motion-notify-event",
            G_CALLBACK (motion_notify_event_cb), NULL);
  g_signal_connect (da, "button-press-event",
            G_CALLBACK (button_press_event_cb), NULL);

  gtk_widget_set_events (da, gtk_widget_get_events (da)
                     | GDK_BUTTON_PRESS_MASK
                     | GDK_POINTER_MOTION_MASK
                     | GDK_POINTER_MOTION_HINT_MASK);

  gtk_widget_show_all (window);

  gtk_main ();

  return 0;
}

#include <QtGui>
#include <QtWidgets>

struct Painter : public QLabel {
    Painter() {
        setPixmap( QPixmap( 600, 480 ) );
        setGraphicsEffect( new QGraphicsBlurEffect );
    }

    void mousePressEvent( QMouseEvent* e ) { s_ = e->pos(); }
    void mouseReleaseEvent( QMouseEvent* ) { s_ = QPoint(); }

    void mouseMoveEvent( QMouseEvent* e ) {
        if( !s_.isNull() ) {
            QPainter p( (QPaintDevice*) pixmap() );
            p.setPen( Qt::white );
            p.drawLine( s_, e->pos() );

            s_ = e->pos();
            update();
        }
    }

    QPoint s_;
};

int main( int argc, char** argv ) {
    QApplication a( argc, argv );
    Painter p;
    p.show();

    return a.exec();
}

~$ kdevelop -v
Qt: 4.8.6
KDE Development Platform: 4.13.0
KDevelop: 4.6.0

(let ((surface nil))
  (defun example-drawing ()
    (within-main-loop
      (let ((window (make-instance 'gtk-window
                                   :type :toplevel
                                   :title "Example Drawing"))
            (frame (make-instance 'gtk-frame
                                  :shadow-type :in))
            (area (make-instance 'gtk-drawing-area
                                 :width-request 250
                                 :height-request 200)))
        (g-signal-connect window "destroy"
                          (lambda (widget)
                            (declare (ignore widget))
                            (leave-gtk-main)))
        ;; Signals used to handle the backing surface
        (g-signal-connect area "draw"
           (lambda (widget cr)
             (declare (ignore widget))
             (let ((cr (pointer cr)))
               (cairo-set-source-surface cr surface 0.0 0.0)
               (cairo-paint cr)
               (cairo-destroy cr)
               +gdk-event-propagate+)))
        (g-signal-connect area "configure-event"
           (lambda (widget event)
             (declare (ignore event))
             (when surface
               (cairo-surface-destroy surface))
             (setf surface
                   (gdk-window-create-similar-surface
                                   (gtk-widget-window widget)
                                   :color
                                   (gtk-widget-get-allocated-width widget)
                                   (gtk-widget-get-allocated-height widget)))
             ;; Clear surface
             (let ((cr (cairo-create surface)))
               (cairo-set-source-rgb cr 1.0 1.0 1.0)
               (cairo-paint cr)
               (cairo-destroy cr))
             (format t "leave event 'configure-event'~%")
             +gdk-event-stop+))
        ;; Event signals
        (g-signal-connect area "motion-notify-event"
           (lambda (widget event)
             (format t "MOTION-NOTIFY-EVENT ~A~%" event)
             (when (member :button1-mask (gdk-event-motion-state event))
               (let ((cr (cairo-create surface))
                     (x (gdk-event-motion-x event))
                     (y (gdk-event-motion-y event)))
                 (cairo-rectangle cr (- x 3.0) (- y 3.0) 6.0 6.0)
                 (cairo-fill cr)
                 (cairo-destroy cr)
                 (gtk-widget-queue-draw-area widget
                                             (truncate (- x 3.0))
                                             (truncate (- y 3.0))
                                             6
                                             6)))
             ;; We have handled the event, stop processing
             +gdk-event-stop+))
        (g-signal-connect area "button-press-event"
           (lambda (widget event)
             (format t "BUTTON-PRESS-EVENT ~A~%" event)
             (if (eql 1 (gdk-event-button-button event))
                 (let ((cr (cairo-create surface))
                       (x (gdk-event-button-x event))
                       (y (gdk-event-button-y event)))
                   (cairo-rectangle cr (- x 3.0) (- y 3.0) 6.0 6.0)
                   (cairo-fill cr)
                   (cairo-destroy cr)
                   (gtk-widget-queue-draw-area widget
                                               (truncate (- x 3.0))
                                               (truncate (- y 3.0))
                                               6
                                               6))
                 ;; Clear surface
                 (let ((cr (cairo-create surface)))
                   (cairo-set-source-rgb cr 1.0 1.0 1.0)
                   (cairo-paint cr)
                   (cairo-destroy cr)
                   (gtk-widget-queue-draw widget)))))
        (gtk-widget-add-events area
                               '(:button-press-mask
                                 :pointer-motion-mask))
        (gtk-container-add frame area)
        (gtk-container-add window frame)
        (gtk-widget-show-all window)))))

QLabel l( QString::fromUtf8( u8"Привет" ) );
l.show();

qDebug() << QString::fromUtf8( u8"Привет" );

vector<string> v { "123", "456" };
for( string s : v )
    s.

vector<string> v { "123", "456" };
for( string s : v )
{
    s.
}

vector<string> v { "123", "456" };
v[ 0 ].

map<string, string> m;
m["test"].