diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoTab.cpp b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoTab.cpp
index 0d459a47d0f..cb93ecbbddb 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoTab.cpp
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoTab.cpp
@@ -23,9 +23,9 @@
 
 ArrangementDemoTabBase::ArrangementDemoTabBase( QWidget* parent ) :
   QWidget( parent ),
-  layout( new QGridLayout( this ) ),
   graphicsView( new ArrangementDemoGraphicsView( this ) ),
   scene( new QGraphicsScene( -100, -100, 100, 100 ) ),
+  layout( new QGridLayout( this ) ),
   arrangementGraphicsItem( NULL ),
   curveInputCallback( NULL ),
   deleteCurveCallback( NULL ),
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoTab.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoTab.h
index 624dfbe57cd..425527ca29e 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoTab.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoTab.h
@@ -48,7 +48,8 @@ public:
   virtual QGraphicsScene* getScene( ) const;
   virtual ArrangementDemoGraphicsView* getView( ) const;
 
-  virtual CGAL::Qt::ArrangementGraphicsItemBase* getArrangementGraphicsItem( ) const;
+  virtual CGAL::Qt::ArrangementGraphicsItemBase* getArrangementGraphicsItem( )
+    const;
   virtual CGAL::Qt::GraphicsViewCurveInputBase* getCurveInputCallback( ) const;
   virtual CGAL::Qt::Callback* getDeleteCurveCallback( ) const;
   virtual CGAL::Qt::Callback* getPointLocationCallback( ) const;
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoWindow.cpp b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoWindow.cpp
index 6a1982276cf..b7c6bbd27eb 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoWindow.cpp
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoWindow.cpp
@@ -37,7 +37,7 @@
 
 ArrangementDemoWindow::ArrangementDemoWindow(QWidget* parent) :
   CGAL::Qt::DemosMainWindow( parent ),
-  lastTabIndex( -1 ),
+  lastTabIndex(static_cast<unsigned int>(-1)),
   ui( new Ui::ArrangementDemoWindow )
 {
   this->setupUi( );
@@ -139,13 +139,8 @@ ArrangementDemoTabBase* ArrangementDemoWindow::makeTab( TraitsType tt )
 ArrangementDemoTabBase* ArrangementDemoWindow::getTab( unsigned int tabIndex )
   const
 {
-  if ( tabIndex < 0 || tabIndex > this->tabs.size( ) )
-  {
-    return NULL;
-  }
-
-  ArrangementDemoTabBase* tab = this->tabs[ tabIndex ];
-  return tab;
+  if (tabIndex > this->tabs.size()) return NULL;
+  return this->tabs[tabIndex];
 }
 
 ArrangementDemoTabBase* ArrangementDemoWindow::getCurrentTab( ) const
@@ -222,8 +217,8 @@ void ArrangementDemoWindow::updateMode( QAction* newMode )
   // QWidget* widget = this->ui->tabWidget->currentWidget( );
   // ArrangementDemoTabBase* demoTab =
   //   static_cast< ArrangementDemoTabBase* >( widget );
-  const int TabIndex = this->ui->tabWidget->currentIndex( );
-  if ( TabIndex == -1 ) return;
+  const unsigned int TabIndex = this->ui->tabWidget->currentIndex( );
+  if (TabIndex == static_cast<unsigned int>(-1)) return;
   ArrangementDemoTabBase* activeTab = this->tabs[ TabIndex ];
   QGraphicsScene* activeScene = activeTab->getScene( );
   QGraphicsView* activeView = activeTab->getView( );
@@ -278,23 +273,18 @@ void ArrangementDemoWindow::updateMode( QAction* newMode )
   this->updateFillColorSwatch( );
 }
 
-void ArrangementDemoWindow::resetCallbackState( int tabIndex )
+void ArrangementDemoWindow::resetCallbackState( unsigned int tabIndex )
 {
-  if ( tabIndex == -1 )
-  {
-    return;
-  }
+  if (tabIndex == static_cast<unsigned int>(-1)) return;
 
   ArrangementDemoTabBase* activeTab = this->tabs[ tabIndex ];
   QAction* activeMode = this->activeModes[ tabIndex ];
 
   // unhook the old active mode
   if ( activeMode == this->ui->actionInsert )
-  {
-  }
+  {  }
   else if ( activeMode == this->ui->actionDrag )
-  {
-  }
+  {  }
   else if ( activeMode == this->ui->actionDelete )
   {
     activeTab->getDeleteCurveCallback( )->reset( );
@@ -325,12 +315,9 @@ void ArrangementDemoWindow::resetCallbackState( int tabIndex )
   }
 }
 
-void ArrangementDemoWindow::removeCallback( int tabIndex )
+void ArrangementDemoWindow::removeCallback( unsigned int tabIndex )
 {
-  if ( tabIndex == -1 )
-  {
-    return;
-  }
+  if (tabIndex == static_cast<unsigned int>(-1)) return;
 
   ArrangementDemoTabBase* activeTab = this->tabs[ tabIndex ];
   QGraphicsScene* activeScene = activeTab->getScene( );
@@ -388,9 +375,8 @@ void ArrangementDemoWindow::removeCallback( int tabIndex )
 
 void ArrangementDemoWindow::updateFillColorSwatch( )
 {
-  int currentTabIndex = this->ui->tabWidget->currentIndex( );
-  if ( currentTabIndex == -1 )
-    return;
+  unsigned int currentTabIndex = this->ui->tabWidget->currentIndex( );
+  if (currentTabIndex == static_cast<unsigned int>(-1)) return;
   ArrangementDemoTabBase* currentTab = this->tabs[ currentTabIndex ];
   FillFaceCallbackBase* fillFaceCallback = currentTab->getFillFaceCallback( );
   QColor fillColor = fillFaceCallback->getColor( );
@@ -1033,11 +1019,10 @@ void ArrangementDemoWindow::on_actionOverlay_triggered( )
 
 void ArrangementDemoWindow::on_actionCloseTab_triggered( )
 {
-  int currentTabIndex = this->ui->tabWidget->currentIndex( );
-  if ( ! this->ui->tabWidget->count( ) || currentTabIndex == -1 )
-  {
+  unsigned int currentTabIndex = this->ui->tabWidget->currentIndex( );
+  if (! this->ui->tabWidget->count() ||
+      (currentTabIndex == static_cast<unsigned int>(-1)))
     return;
-  }
 
   // delete the tab
   this->ui->tabWidget->removeTab( currentTabIndex );
@@ -1051,8 +1036,7 @@ void ArrangementDemoWindow::on_actionPrintConicCurves_triggered( )
 {
   // int currentTabIndex = this->ui->tabWidget->currentIndex( );
   // Conic_arr* arr;
-  // if ( currentTabIndex == -1 )
-  //     return;
+  // if (currentTabIndex == static_cast<unsigned int>(-1)) return;
   // CGAL::Object o = this->arrangements[ currentTabIndex ];
   // if ( ! CGAL::assign( arr, o ) )
   //     return;
@@ -1103,10 +1087,8 @@ void ArrangementDemoWindow::on_actionPrintConicCurves_triggered( )
 
 void ArrangementDemoWindow::on_actionZoomIn_triggered( )
 {
-  int currentTabIndex = this->ui->tabWidget->currentIndex( );
-  if ( currentTabIndex == -1 )
-    return;
-
+  unsigned int currentTabIndex = this->ui->tabWidget->currentIndex( );
+  if (currentTabIndex == static_cast<unsigned int>(-1)) return;
   ArrangementDemoTabBase* currentTab = this->tabs[ currentTabIndex ];
   QGraphicsView* view = currentTab->getView( );
   view->scale( 2.0, 2.0 );
@@ -1114,10 +1096,8 @@ void ArrangementDemoWindow::on_actionZoomIn_triggered( )
 
 void ArrangementDemoWindow::on_actionZoomOut_triggered( )
 {
-  int currentTabIndex = this->ui->tabWidget->currentIndex( );
-  if ( currentTabIndex == -1 )
-    return;
-
+  unsigned int currentTabIndex = this->ui->tabWidget->currentIndex( );
+  if (currentTabIndex == static_cast<unsigned int>(-1)) return;
   ArrangementDemoTabBase* currentTab = this->tabs[ currentTabIndex ];
   QGraphicsView* view = currentTab->getView( );
   view->scale( 0.5, 0.5 );
@@ -1125,14 +1105,15 @@ void ArrangementDemoWindow::on_actionZoomOut_triggered( )
 
 void ArrangementDemoWindow::on_actionPreferences_triggered( )
 {
-  int currentTabIndex = this->ui->tabWidget->currentIndex( );
-  if ( currentTabIndex == -1 )
-    return;
+  unsigned int currentTabIndex = this->ui->tabWidget->currentIndex( );
+  if (currentTabIndex == static_cast<unsigned int>(-1)) return;
   ArrangementDemoTabBase* currentTab = this->tabs[ currentTabIndex ];
-  CGAL::Qt::ArrangementGraphicsItemBase* agi = currentTab->getArrangementGraphicsItem( );
+  CGAL::Qt::ArrangementGraphicsItemBase* agi =
+    currentTab->getArrangementGraphicsItem( );
   ArrangementDemoGraphicsView* view = currentTab->getView( );
   EnvelopeCallbackBase* envelopeCallback = currentTab->getEnvelopeCallback( );
-  VerticalRayShootCallbackBase* verticalRayShootCallback = currentTab->getVerticalRayShootCallback( );
+  VerticalRayShootCallbackBase* verticalRayShootCallback =
+    currentTab->getVerticalRayShootCallback( );
   SplitEdgeCallbackBase* splitEdgeCallback = currentTab->getSplitEdgeCallback( );
     
 #if 0
@@ -1210,9 +1191,8 @@ void ArrangementDemoWindow::on_actionPreferences_triggered( )
 
 void ArrangementDemoWindow::on_actionFillColor_triggered( )
 {
-  int currentTabIndex = this->ui->tabWidget->currentIndex( );
-  if ( currentTabIndex == -1 )
-    return;
+  unsigned int currentTabIndex = this->ui->tabWidget->currentIndex( );
+  if (currentTabIndex == static_cast<unsigned int>(-1)) return;
   ArrangementDemoTabBase* currentTab = this->tabs[ currentTabIndex ];
   FillFaceCallbackBase* fillFaceCallback = currentTab->getFillFaceCallback( );
   QColor fillColor = fillFaceCallback->getColor( );
@@ -1221,7 +1201,6 @@ void ArrangementDemoWindow::on_actionFillColor_triggered( )
   if ( selectedColor.isValid( ) )
   {
     fillFaceCallback->setColor( selectedColor );
-
     this->updateFillColorSwatch( );
   }
 }
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoWindow.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoWindow.h
index bcfcc6db3d2..5f6c864c8c4 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoWindow.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementDemoWindow.h
@@ -102,8 +102,8 @@ signals:
 
 protected:
   void setupUi( );
-  void resetCallbackState( int tabIndex );
-  void removeCallback( int tabIndex );
+  void resetCallbackState( unsigned int tabIndex );
+  void removeCallback( unsigned int tabIndex );
   void updateFillColorSwatch( );
 
   void openArrFile( QString filename );
@@ -112,7 +112,7 @@ protected:
   std::vector< ArrangementDemoTabBase* > tabs;
   std::vector< CGAL::Object > arrangements;
   std::vector< QAction* > activeModes; // for the current tab
-  int lastTabIndex;
+  unsigned int lastTabIndex;
 
   Ui::ArrangementDemoWindow* ui;
   QActionGroup* modeGroup;
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementGraphicsItem.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementGraphicsItem.h
index b293c886f69..ada98f03b78 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementGraphicsItem.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementGraphicsItem.h
@@ -22,7 +22,8 @@
 
 #include <CGAL/Bbox_2.h>
 //#include <CGAL/apply_to_range.h>
-//#include <CGAL/Kernel/global_functions.h> // TODO: should be included in PainterOstream.h
+// TODO: should be included in PainterOstream.h
+//#include <CGAL/Kernel/global_functions.h>
 #include <CGAL/Qt/GraphicsItem.h>
 #include <CGAL/Qt/Converter.h>
 #include <CGAL/Arr_circular_arc_traits_2.h>
@@ -79,25 +80,25 @@ template <typename Arr_, typename ArrTraits = typename Arr_::Geometry_traits_2>
 class ArrangementGraphicsItem : public ArrangementGraphicsItemBase
 {
   typedef Arr_ Arrangement;
-  typedef typename Arrangement::Geometry_traits_2 Traits;
-  typedef typename Arrangement::Vertex_iterator Vertex_iterator;
-  typedef typename Arrangement::Curve_iterator Curve_iterator;
-  typedef typename Arrangement::Edge_iterator Edge_iterator;
-  typedef typename Arrangement::Halfedge Halfedge;
-  typedef typename Arrangement::Halfedge_handle Halfedge_handle;
-  typedef typename Arrangement::Face_handle Face_handle;
-  typedef typename Arrangement::Face_iterator Face_iterator;
-  typedef typename Arrangement::Hole_iterator Holes_iterator;
+  typedef typename Arrangement::Geometry_traits_2       Traits;
+  typedef typename Arrangement::Vertex_iterator         Vertex_iterator;
+  typedef typename Arrangement::Curve_iterator          Curve_iterator;
+  typedef typename Arrangement::Edge_iterator           Edge_iterator;
+  typedef typename Arrangement::Halfedge                Halfedge;
+  typedef typename Arrangement::Halfedge_handle         Halfedge_handle;
+  typedef typename Arrangement::Face_handle             Face_handle;
+  typedef typename Arrangement::Face_iterator           Face_iterator;
+  typedef typename Arrangement::Hole_iterator           Holes_iterator;
   typedef typename Arrangement::Ccb_halfedge_circulator Ccb_halfedge_circulator;
  
-  typedef typename ArrTraitsAdaptor< Traits >::Kernel Kernel;
-  typedef typename Traits::X_monotone_curve_2 X_monotone_curve_2;
-  typedef typename Kernel::Point_2 Kernel_point_2;
-  typedef typename Traits::Point_2 Point_2;
+  typedef typename ArrTraitsAdaptor< Traits >::Kernel   Kernel;
+  typedef typename Traits::X_monotone_curve_2           X_monotone_curve_2;
+  typedef typename Kernel::Point_2                      Kernel_point_2;
+  typedef typename Traits::Point_2                      Point_2;
   //typedef typename Kernel::Segment_2 Segment_2;
 
-  typedef ArrangementGraphicsItemBase Superclass;
-  typedef typename Kernel::Segment_2 Segment_2;
+  typedef ArrangementGraphicsItemBase                   Superclass;
+  typedef typename Kernel::Segment_2                    Segment_2;
 
 public:
   ArrangementGraphicsItem( Arrangement* t_ );
@@ -239,7 +240,10 @@ protected:
   }
 
   template < typename Traits >
-  void paintFace( Face_handle f, QPainter* painter, Traits traits ) { }
+  void paintFace(Face_handle /* f */, QPainter* /* painter */,
+                 Traits /* traits */)
+  { }
+
   template < typename Kernel_ >
   void paintFace( Face_handle f, QPainter* painter,
                   CGAL::Arr_segment_traits_2< Kernel_ > )
@@ -468,8 +472,8 @@ protected:
   }
 
   template < typename CircularKernel >
-  void paintFace( Face_handle f, QPainter* painter,
-                  CGAL::Arr_circular_arc_traits_2< CircularKernel > traits )
+  void paintFace(Face_handle f, QPainter* painter,
+                 CGAL::Arr_circular_arc_traits_2<CircularKernel> /* traits */)
   {
     if ( f->is_unbounded( ) )
     {
@@ -624,8 +628,8 @@ protected:
 
 #if 0
   template < typename CircularKernel >
-  void paintFace( Face_handle f, QPainter* painter,
-                  CGAL::Arr_circular_arc_traits_2< CircularKernel > traits )
+  void paintFace(Face_handle f, QPainter* painter,
+                 CGAL::Arr_circular_arc_traits_2<CircularKernel> /* traits */)
   {
     // std::cout << "face begin" << std::endl;
     if (! f->is_unbounded())  // f is not the unbounded face
@@ -825,7 +829,7 @@ protected:
   void 
   ArrangementGraphicsItem< Arr_, ArrTraits >::
   paint(QPainter* painter,
-        const QStyleOptionGraphicsItem* option,
+        const QStyleOptionGraphicsItem* /* option */,
         QWidget*  /*widget*/)
   {
     this->paint( painter, ArrTraits( ) );
@@ -834,7 +838,7 @@ protected:
   template < typename Arr_, typename ArrTraits >
   template < typename TTraits >
   void ArrangementGraphicsItem< Arr_, ArrTraits >::
-  paint( QPainter* painter, TTraits traits )
+  paint(QPainter* painter, TTraits /* traits */)
   {
     this->paintFaces( painter );
 
@@ -861,9 +865,8 @@ protected:
 
   template < typename Arr_, typename ArrTraits >
   template < typename Kernel_ >
-  void
-  ArrangementGraphicsItem< Arr_, ArrTraits >::
-  paint( QPainter* painter, CGAL::Arr_linear_traits_2< Kernel_ > traits )
+  void ArrangementGraphicsItem< Arr_, ArrTraits >::
+  paint(QPainter* painter, CGAL::Arr_linear_traits_2< Kernel_ > /* traits */)
   {
     this->updateBoundingBox( );
     this->paintFaces( painter );
@@ -890,10 +893,9 @@ protected:
 
   template < typename Arr_, typename ArrTraits >
   template < typename CircularKernel >
-  void
-  ArrangementGraphicsItem< Arr_, ArrTraits >::
-  paint( QPainter* painter,
-         CGAL::Arr_circular_arc_traits_2< CircularKernel > traits )
+  void ArrangementGraphicsItem< Arr_, ArrTraits >::
+  paint(QPainter* painter,
+        CGAL::Arr_circular_arc_traits_2< CircularKernel > /* traits */)
   {
     typedef Kernel_point_2 Non_arc_point_2;
     typedef typename Traits::Point_2 Arc_point_2;
@@ -923,10 +925,9 @@ protected:
 
   template < typename Arr_, typename ArrTraits >
   template < typename Coefficient_ >
-  void
-  ArrangementGraphicsItem< Arr_, ArrTraits >::
-  paint( QPainter* painter,
-         CGAL::Arr_algebraic_segment_traits_2< Coefficient_ > traits )
+  void ArrangementGraphicsItem< Arr_, ArrTraits >::
+  paint(QPainter* painter,
+        CGAL::Arr_algebraic_segment_traits_2< Coefficient_ > /* traits */)
   {
     painter->setPen( this->verticesPen );
     QRectF clipRect = this->boundingRect( );
@@ -963,16 +964,15 @@ protected:
   // We let the bounding box only grow, so that when vertices get removed
   // the maximal bbox gets refreshed in the GraphicsView
   template < typename Arr_, typename ArrTraits >
-  void 
-  ArrangementGraphicsItem< Arr_, ArrTraits >::updateBoundingBox( )
+  void ArrangementGraphicsItem< Arr_, ArrTraits >::updateBoundingBox( )
   {
     this->updateBoundingBox( ArrTraits( ) );
   }
 
   template < typename Arr_, typename ArrTraits >
   template < typename TTraits >
-  void 
-  ArrangementGraphicsItem< Arr_, ArrTraits >::updateBoundingBox(TTraits traits)
+  void ArrangementGraphicsItem< Arr_, ArrTraits >::
+  updateBoundingBox(TTraits /* traits */)
   {
     this->prepareGeometryChange( );
     if ( this->arr->number_of_vertices( ) == 0 )
@@ -998,11 +998,12 @@ protected:
       this->bb = this->bb + this->curveBboxMap[ it ];
     }
   }
+
   template < typename Arr_, typename ArrTraits >
   template < typename Kernel_ >
   void
   ArrangementGraphicsItem< Arr_, ArrTraits >::
-  updateBoundingBox( CGAL::Arr_linear_traits_2< Kernel_ > traits )
+  updateBoundingBox(CGAL::Arr_linear_traits_2< Kernel_ > /* traits */)
   {
     this->prepareGeometryChange( );
     QRectF clipRect = this->viewportRect( );
@@ -1062,14 +1063,15 @@ protected:
       this->bb = CGAL::Bbox_2( 0, 0, 0, 0 );
       this->bb_initialized = true;
     }
-    typename Traits::Make_x_monotone_2 make_x_monotone_2 = traits.make_x_monotone_2_object( );
+    typename Traits::Make_x_monotone_2 make_x_monotone_2 =
+      traits.make_x_monotone_2_object( );
     for ( Curve_iterator it = this->arr->curves_begin( );
           it != this->arr->curves_end( );
           ++it )
     {
       std::vector< CGAL::Object > cvs;
       make_x_monotone_2( *it, std::back_inserter( cvs ) );
-      for ( int i = 0 ; i < cvs.size( ); ++i )
+      for ( unsigned int i = 0 ; i < cvs.size( ); ++i )
       {
         X_monotone_curve_2 cv;
         CGAL::assign( cv, cvs[ i ] );
@@ -1104,14 +1106,14 @@ protected:
   {
     typedef Arr_ Arrangement;
     typedef ArrangementGraphicsItemBase Superclass;
-    typedef typename Arrangement::Geometry_traits_2 Traits;
-    typedef typename Arrangement::Vertex_iterator Vertex_iterator;
-    typedef typename Arrangement::Curve_iterator Curve_iterator;
-    typedef typename Arrangement::Edge_iterator Edge_iterator;
+    typedef typename Arrangement::Geometry_traits_2     Traits;
+    typedef typename Arrangement::Vertex_iterator       Vertex_iterator;
+    typedef typename Arrangement::Curve_iterator        Curve_iterator;
+    typedef typename Arrangement::Edge_iterator         Edge_iterator;
     typedef typename ArrTraitsAdaptor< Traits >::Kernel Kernel;
-    typedef typename Traits::X_monotone_curve_2 X_monotone_curve_2;
-    typedef typename Kernel::Point_2 Point_2;
-    typedef typename Kernel::Segment_2 Segment_2;
+    typedef typename Traits::X_monotone_curve_2         X_monotone_curve_2;
+    typedef typename Kernel::Point_2                    Point_2;
+    typedef typename Kernel::Segment_2                  Segment_2;
 
   public:
     ArrangementGraphicsItem( Arrangement* arr_ ):
@@ -1157,7 +1159,8 @@ protected:
     {
       this->updateBoundingBox( );
       painter->setPen( this->verticesPen );
-      this->painterostream = ArrangementPainterOstream< Traits >( painter, this->boundingRect( ) );
+      this->painterostream =
+        ArrangementPainterOstream< Traits >( painter, this->boundingRect( ) );
       this->painterostream.setScene( this->scene );
 
       for ( Vertex_iterator it = this->arr->vertices_begin( );
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementPainterOstream.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementPainterOstream.h
index 4aefd412d8b..cc043811e11 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementPainterOstream.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementPainterOstream.h
@@ -248,7 +248,7 @@ public: // constructors
 public: // methods
   ArrangementPainterOstream& operator<<( const X_monotone_curve_2& curve )
   {
-    for ( int i = 0; i < curve.size( ); ++i )
+    for ( unsigned int i = 0; i < curve.size( ); ++i )
     {
       Segment_2 segment = curve[ i ];
       this->painterOstream << segment;
@@ -374,7 +374,7 @@ public: // methods
       {
         visibleParts = this->visibleParts( curve );
       }
-      for ( int i = 0; i < visibleParts.size( ); ++i )
+      for ( unsigned int i = 0; i < visibleParts.size( ); ++i )
       {
         X_monotone_curve_2 subcurve = visibleParts[ i ];
         int n;
@@ -513,10 +513,10 @@ protected: // methods
     intersect_2( left, curve, std::back_inserter( leftIntersections ) );
     intersect_2( top, curve, std::back_inserter( topIntersections ) );
     intersect_2( right, curve, std::back_inserter( rightIntersections ) );
-    int total = bottomIntersections.size( )
-      + leftIntersections.size( )
-      + topIntersections.size( )
-      + rightIntersections.size( );
+    // int total = bottomIntersections.size( )
+    //   + leftIntersections.size( )
+    //   + topIntersections.size( )
+    //   + rightIntersections.size( );
 
     intersect_2( bottom, curve, std::back_inserter( intersections ) );
     intersect_2( left, curve, std::back_inserter( intersections ) );
@@ -537,7 +537,7 @@ protected: // methods
     QPointF qendpt1 = this->convert( leftEndpt );
     QPointF qendpt2 = this->convert( rightEndpt );
     std::list< Point_2 > pointList;
-    for ( int i = 0; i < intersections.size( ); ++i )
+    for ( unsigned int i = 0; i < intersections.size( ); ++i )
     {
       CGAL::Object o = intersections[ i ];
       std::pair< Intersection_point_2, Multiplicity > pair;
@@ -557,7 +557,7 @@ protected: // methods
     Construct_x_monotone_subcurve_2< Traits > construct_x_monotone_subcurve_2;
     std::vector< X_monotone_curve_2 > clippings;
     typename std::list< Point_2 >::iterator pointListItr = pointList.begin( );
-    for ( int i = 0; i < pointList.size( ); i += 2 )
+    for ( unsigned int i = 0; i < pointList.size( ); i += 2 )
     {
       Point_2 p1 = *pointListItr++;
       Point_2 p2 = *pointListItr++;
@@ -608,7 +608,7 @@ protected: // methods
     std::vector< std::pair< Intersection_point_2, Multiplicity > > tmp;
 
     // filter out the non-intersection point results
-    for ( int i = 0; i < res.size( ); ++i )
+    for ( unsigned int i = 0; i < res.size( ); ++i )
     {
       CGAL::Object obj = res[ i ];
       std::pair< Intersection_point_2, Multiplicity > pair;
@@ -624,7 +624,7 @@ protected: // methods
     std::sort( tmp.begin( ), tmp.end( ), compare_intersection_point_result );
 
     // box up the sorted elements
-    for ( int i = 0; i < tmp.size( ); ++i )
+    for ( unsigned int i = 0; i < tmp.size( ); ++i )
     {
       std::pair< Intersection_point_2, Multiplicity > pair = tmp[ i ];
       CGAL::Object o = CGAL::make_object( pair );
@@ -845,10 +845,9 @@ public: // methods
     if(points.empty()) 
       return *this;
             
-    QPainter *ppnt = this->qp;
+    // QPainter *ppnt = this->qp;
     QGraphicsView* view = this->scene->views( ).first( );
-    int height = view->height();
-
+    // int height = view->height();
     // std::cerr << ws.width() << " and " <<  ws.height() << "\n";
     typename std::list<Coord_vec_2>::const_iterator lit = points.begin();
     //ppnt->moveTo((*p1).first, height - (*p1).second);
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/Callback.cpp b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/Callback.cpp
index 6d1fe63a0ef..19d1a6fecf5 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/Callback.cpp
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/Callback.cpp
@@ -60,13 +60,13 @@ bool Callback::eventFilter( QObject* object, QEvent* event )
   return QObject::eventFilter( object, event );
 }
 
-void Callback::mousePressEvent( QGraphicsSceneMouseEvent* event ) { }
+  void Callback::mousePressEvent(QGraphicsSceneMouseEvent* /* event */) { }
 
-void Callback::mouseMoveEvent( QGraphicsSceneMouseEvent* event ) { }
+  void Callback::mouseMoveEvent(QGraphicsSceneMouseEvent* /* event */) { }
 
-void Callback::mouseReleaseEvent( QGraphicsSceneMouseEvent* event ) { }
+  void Callback::mouseReleaseEvent(QGraphicsSceneMouseEvent* /* event */) { }
 
-void Callback::keyPressEvent( QKeyEvent* event ) { }
+  void Callback::keyPressEvent(QKeyEvent* /* event */)  { }
 
 void Callback::slotModelChanged( ) { }
 
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/CurveGraphicsItem.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/CurveGraphicsItem.h
index 78e5f1ec0b8..074d59d4e3b 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/CurveGraphicsItem.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/CurveGraphicsItem.h
@@ -59,9 +59,9 @@ public: // ctors
   }
 
 public: // methods
-  virtual void paint( QPainter* painter,
-                      const QStyleOptionGraphicsItem* option,
-                      QWidget* widget )
+  virtual void paint(QPainter* painter,
+                     const QStyleOptionGraphicsItem* /* option */,
+                     QWidget* /* widget */)
   {
     // draw the curves
     QPen edgesPen( this->m_edgeColor, this->m_edgeWidth );
@@ -70,7 +70,7 @@ public: // methods
     this->painterOstream =
       ArrangementPainterOstream< Traits >( painter, clippingRectangle );
     this->painterOstream.setScene( this->getScene( ) );
-    for ( int i = 0; i < this->curves.size( ); ++i )
+    for ( unsigned int i = 0; i < this->curves.size( ); ++i )
     {
       X_monotone_curve_2 curve = this->curves[ i ];
       this->painterOstream << curve;
@@ -79,7 +79,7 @@ public: // methods
     // draw the points
     QPen verticesPen( this->m_vertexColor, this->m_vertexRadius );
     painter->setPen( verticesPen );
-    for ( int i = 0; i < this->points.size( ); ++i )
+    for ( unsigned int i = 0; i < this->points.size( ); ++i )
     {
       Point_2 arrPoint = this->points[ i ];
       Kernel_point_2 point( CGAL::to_double( arrPoint.x( ) ),
@@ -188,15 +188,15 @@ protected: // methods
       this->boundingBoxInitialized = true;
     }
 
-    for ( int i = 1; i < this->curves.size( ); ++i )
+    for ( unsigned int i = 1; i < this->curves.size( ); ++i )
     {
       this->boundingBox = this->boundingBox + this->curves[ i ].bbox( );
     }
 
-    for ( int i = 0; i < this->points.size( ); ++i )
+    for ( unsigned int i = 0; i < this->points.size( ); ++i )
     {
       Point_2 pt = this->points[ i ];
-      Kernel_point_2 point( CGAL::to_double( pt.x( ) ), CGAL::to_double( pt.y( ) ) );
+      Kernel_point_2 point(CGAL::to_double(pt.x()), CGAL::to_double(pt.y()));
       this->boundingBox = this->boundingBox + point.bbox( );
     }
   }
@@ -227,15 +227,15 @@ class CurveGraphicsItem< CGAL::Arr_linear_traits_2< Kernel_ > > :
 {
 public: // typedefs
   // known curve types
-  typedef CGAL::Arr_linear_traits_2< Kernel_ > Traits;
+  typedef CGAL::Arr_linear_traits_2< Kernel_ >          Traits;
   typedef Kernel_ Kernel;
-  typedef typename Traits::Curve_2 Curve_2;
-  typedef typename Traits::X_monotone_curve_2 X_monotone_curve_2;
-  typedef typename Traits::Point_2 Point_2;
-  typedef typename Kernel::Segment_2 Segment_2;
-  typedef typename Kernel::Line_2 Line_2;
-  typedef typename Kernel::Ray_2 Ray_2;
-  typedef typename Kernel::Point_2 Kernel_point_2;
+  typedef typename Traits::Curve_2                      Curve_2;
+  typedef typename Traits::X_monotone_curve_2           X_monotone_curve_2;
+  typedef typename Traits::Point_2                      Point_2;
+  typedef typename Kernel::Segment_2                    Segment_2;
+  typedef typename Kernel::Line_2                       Line_2;
+  typedef typename Kernel::Ray_2                        Ray_2;
+  typedef typename Kernel::Point_2                      Kernel_point_2;
 
 public: // ctors
   CurveGraphicsItem( ):
@@ -247,18 +247,20 @@ public: // ctors
   }
 
 public: // methods
-  virtual void paint( QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget )
+  virtual void paint(QPainter* painter,
+                     const QStyleOptionGraphicsItem* /* option */,
+                     QWidget* /* widget */)
   {
     QRectF clippingRectangle = this->viewportRect( );
     painter->setPen( QPen( ::Qt::red, 0. ) );
     this->painterOstream =
       ArrangementPainterOstream< Traits >( painter, clippingRectangle );
-    for ( int i = 0; i < this->curves.size( ); ++i )
+    for ( unsigned int i = 0; i < this->curves.size( ); ++i )
     {
       X_monotone_curve_2 curve = this->curves[ i ];
       this->painterOstream << curve;
     }
-    for ( int i = 0; i < this->points.size( ); ++i )
+    for ( unsigned int i = 0; i < this->points.size( ); ++i )
     {
       Point_2 arrPoint = this->points[ i ];
       Kernel_point_2 point( CGAL::to_double( arrPoint.x( ) ),
@@ -270,7 +272,6 @@ public: // methods
   void insert( const X_monotone_curve_2& curve )
   {
     this->curves.push_back( curve );
-
     this->updateBoundingBox( );
   }
 
@@ -372,7 +373,7 @@ protected: // methods
     this->convert = CGAL::Qt::Converter< Kernel >( clipRect );
 
     bool first = 1;
-    for ( int i = 0; i < curves.size( ); ++i )
+    for ( unsigned int i = 0; i < curves.size( ); ++i )
     {
       X_monotone_curve_2 curve = curves[ i ];
       if ( curve.is_segment( ) )
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/DeleteCurveCallback.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/DeleteCurveCallback.h
index d9af6095cff..2023d76f542 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/DeleteCurveCallback.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/DeleteCurveCallback.h
@@ -113,7 +113,7 @@ void DeleteCurveCallback< Arr_ >::reset( )
 
 template < typename Arr_ >
 void 
-DeleteCurveCallback< Arr_ >::mousePressEvent( QGraphicsSceneMouseEvent* event )
+DeleteCurveCallback<Arr_>::mousePressEvent(QGraphicsSceneMouseEvent* /* event */)
 {
   if ( this->removableHalfedge == Halfedge_handle( ) )
   {
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/EnvelopeCallback.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/EnvelopeCallback.h
index d4c41986304..d7104045fdf 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/EnvelopeCallback.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/EnvelopeCallback.h
@@ -52,7 +52,7 @@ protected:
 /**
    Updates and draws the lower and upper envelopes of an observed arrangement.
 */
-template < class Arr_, class Traits = typename Arr_::Geometry_traits_2 >
+template < typename Arr_, typename Traits = typename Arr_::Geometry_traits_2 >
 class EnvelopeCallback : public EnvelopeCallbackBase
 {
 public:
@@ -61,13 +61,13 @@ public:
   //typedef typename Arrangement::Geometry_traits_2 Traits;
   typedef typename Traits::X_monotone_curve_2 X_monotone_curve_2;
   //typedef typename Traits::Construct_x_monotone_curve_2 Construct_x_monotone_curve_2;
-  typedef typename ArrTraitsAdaptor< Traits >::Kernel Kernel;
-  typedef typename Kernel::Point_2 Kernel_point_2;
-  typedef typename Traits::Point_2 Point_2;
-  typedef typename Kernel::Segment_2 Segment_2;
-  typedef typename Kernel::Ray_2 Ray_2;
-  typedef typename Kernel::Line_2 Line_2;
-  typedef CGAL::Envelope_diagram_1< Traits > Diagram_1;
+  typedef typename ArrTraitsAdaptor< Traits >::Kernel   Kernel;
+  typedef typename Kernel::Point_2                      Kernel_point_2;
+  typedef typename Traits::Point_2                      Point_2;
+  typedef typename Kernel::Segment_2                    Segment_2;
+  typedef typename Kernel::Ray_2                        Ray_2;
+  typedef typename Kernel::Line_2                       Line_2;
+  typedef CGAL::Envelope_diagram_1< Traits >            Diagram_1;
 
   /**
      Construct an envelope callback observing the given arrangement.
@@ -142,14 +142,14 @@ protected:
   */
   void updateEnvelope( bool lower );
 
-  template < class TTraits >
+  template < typename TTraits >
   void updateEnvelope( bool lower, TTraits traits );
 
-  template < class CircularKernel >
+  template < typename CircularKernel >
   void updateEnvelope(bool lower,
                       CGAL::Arr_circular_arc_traits_2<CircularKernel> traits);
 
-  template < class Coefficient_ >
+  template < typename Coefficient_ >
   void updateEnvelope(bool lower,
                       CGAL::Arr_algebraic_segment_traits_2<Coefficient_> traits);
 
@@ -160,7 +160,7 @@ protected:
   using CGAL::Qt::Callback::scene;
 }; // class EnvelopeCallback
 
-template < class Arr_, class Traits >
+template < typename Arr_, typename Traits >
 EnvelopeCallback< Arr_, Traits >::
 EnvelopeCallback( Arrangement* arr_, QObject* parent ):
   EnvelopeCallbackBase( parent ),
@@ -172,28 +172,23 @@ EnvelopeCallback( Arrangement* arr_, QObject* parent ):
   this->upperEnvelope->hide( );
 }
 
-template < class Arr_, class Traits >
-void
-EnvelopeCallback< Arr_, Traits >::
-slotModelChanged( )
+template < typename Arr_, typename Traits >
+void EnvelopeCallback< Arr_, Traits >::slotModelChanged( )
 {
   this->updateEnvelope( true );
   this->updateEnvelope( false );
 }
 
-template < class Arr_, class Traits >
-void
-EnvelopeCallback< Arr_, Traits >::
-updateEnvelope( bool lower )
+template < typename Arr_, typename Traits >
+void EnvelopeCallback< Arr_, Traits >::updateEnvelope( bool lower )
 {
   this->updateEnvelope( lower, Traits( ) );
 }
 
-template < class Arr_, class Traits >
-template < class TTraits >
-void
-EnvelopeCallback< Arr_, Traits >::
-updateEnvelope( bool lower, TTraits traits )
+template < typename Arr_, typename Traits >
+template < typename TTraits >
+void EnvelopeCallback< Arr_, Traits >::updateEnvelope(bool lower,
+                                                      TTraits /* traits */)
 {
   CGAL::Qt::CurveGraphicsItem< Traits >* envelopeToUpdate;
   if ( lower )
@@ -273,12 +268,12 @@ updateEnvelope( bool lower, TTraits traits )
   envelopeToUpdate->modelChanged( );
 }
 
-template < class Arr_, class Traits >
-template < class CircularKernel >
+template < typename Arr_, typename Traits >
+template < typename CircularKernel >
 void
 EnvelopeCallback< Arr_, Traits >::
-updateEnvelope( bool lower,
-                CGAL::Arr_circular_arc_traits_2< CircularKernel > traits )
+updateEnvelope(bool lower,
+               CGAL::Arr_circular_arc_traits_2< CircularKernel > /* traits */)
 {
   typedef Kernel_point_2 Non_arc_point_2;
   typedef typename Traits::Point_2 Arc_point_2;
@@ -294,7 +289,8 @@ updateEnvelope( bool lower,
   envelopeToUpdate->clear( );
 
   std::list< X_monotone_curve_2 > curves;
-  for ( Edge_iterator eit = this->arr->edges_begin( ); eit != this->arr->edges_end( ); ++eit )
+  for ( Edge_iterator eit =
+          this->arr->edges_begin( ); eit != this->arr->edges_end( ); ++eit )
   {
     curves.push_back( eit->curve( ) );
   }
@@ -358,19 +354,17 @@ updateEnvelope( bool lower,
   envelopeToUpdate->modelChanged( );
 }
 
-template < class Arr_, class Traits >
-template < class Coefficient_ >
-void
-EnvelopeCallback< Arr_, Traits >::
-updateEnvelope( bool lower,
-                CGAL::Arr_algebraic_segment_traits_2< Coefficient_ > traits )
+template < typename Arr_, typename Traits >
+template < typename Coefficient_ >
+void EnvelopeCallback< Arr_, Traits >::
+updateEnvelope(bool /* lower */,
+               CGAL::Arr_algebraic_segment_traits_2< Coefficient_ > /* traits */)
 {
   // std::cout << "alg seg envelope stub" << std::endl;
 }
 
-template < class Arr_, class Traits >
-void
-EnvelopeCallback< Arr_, Traits >::showLowerEnvelope( bool show )
+template < typename Arr_, typename Traits >
+void EnvelopeCallback< Arr_, Traits >::showLowerEnvelope( bool show )
 {
   if ( show )
   {
@@ -384,9 +378,8 @@ EnvelopeCallback< Arr_, Traits >::showLowerEnvelope( bool show )
   }
 }
 
-template < class Arr_, class Traits >
-void
-EnvelopeCallback< Arr_, Traits >::showUpperEnvelope( bool show )
+template < typename Arr_, typename Traits >
+void EnvelopeCallback< Arr_, Traits >::showUpperEnvelope( bool show )
 {
   if ( show )
   {
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/FillFaceCallback.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/FillFaceCallback.h
index fedfb9a0ba6..44467d0f129 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/FillFaceCallback.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/FillFaceCallback.h
@@ -135,7 +135,7 @@ void FillFaceCallback<Arr_>::mousePressEvent(QGraphicsSceneMouseEvent* event)
 
 template < class Arr_ >
 void 
-FillFaceCallback< Arr_ >::mouseMoveEvent( QGraphicsSceneMouseEvent* event )
+FillFaceCallback< Arr_ >::mouseMoveEvent(QGraphicsSceneMouseEvent* /* event */)
 { }
 
 template < class Arr_ >
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/GraphicsViewCurveInput.cpp b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/GraphicsViewCurveInput.cpp
index 631968d049d..cf791925119 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/GraphicsViewCurveInput.cpp
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/GraphicsViewCurveInput.cpp
@@ -63,11 +63,11 @@ GraphicsViewCurveInputBase::GraphicsViewCurveInputBase( QObject* parent ) :
 }
 
 void
-GraphicsViewCurveInputBase::mouseMoveEvent( QGraphicsSceneMouseEvent* event )
+GraphicsViewCurveInputBase::mouseMoveEvent(QGraphicsSceneMouseEvent* /* event */)
 { }
 
-void
-GraphicsViewCurveInputBase::mousePressEvent( QGraphicsSceneMouseEvent* event )
+void GraphicsViewCurveInputBase::
+mousePressEvent(QGraphicsSceneMouseEvent* /* event */)
 { 
   // std::cout << "GraphicsViewCurveInputBase::mousePressEvent" << std::endl;
 }
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/GraphicsViewCurveInput.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/GraphicsViewCurveInput.h
index dee3300024d..1804effdc8d 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/GraphicsViewCurveInput.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/GraphicsViewCurveInput.h
@@ -223,7 +223,7 @@ protected:
 
       if ( event->button( ) == ::Qt::RightButton )
       { // finalize polyline input
-        for ( int i = 0; i < this->polylineGuide.size( ); ++i )
+        for ( unsigned int i = 0; i < this->polylineGuide.size( ); ++i )
         {
           if ( this->scene != NULL )
           {
@@ -338,7 +338,7 @@ protected:
       QPointF p2 = this->convert( this->snapPoint( event ) );
       double radius = sqrt( (p1.x( ) - p2.x( ))*(p1.x( ) - p2.x( ))
                             + (p1.y( ) - p2.y( ))*(p1.y( ) - p2.y( )) );
-      double d = radius * sqrt( 2.0 );
+      // double d = radius * sqrt( 2.0 );
       this->circleItem->setRect( p1.x( ) - radius, p1.y( ) -
                                  radius, 2*radius, 2*radius );
     }
@@ -411,7 +411,7 @@ protected:
     {
       if ( this->conicType == CONIC_SEGMENT )
       {
-        for ( int i = 0; i < this->polylineGuide.size( ); ++i )
+        for ( unsigned int i = 0; i < this->polylineGuide.size( ); ++i )
         {
           if ( this->scene != NULL )
           {
@@ -467,7 +467,7 @@ protected:
         double y1 = CGAL::to_double( bb.ymin( ) );
         double x2 = CGAL::to_double( bb.xmax( ) );
         double y2 = CGAL::to_double( bb.ymax( ) );
-        double sq_rad = CGAL::square(x2 - x1) + CGAL::square(y2 - y1);
+        // double sq_rad = CGAL::square(x2 - x1) + CGAL::square(y2 - y1);
 
         Rat_FT a = CORE::abs( Rat_FT(x1) - Rat_FT(x2) )/2;
         Rat_FT b = CORE::abs( Rat_FT(y1) - Rat_FT(y2) )/2;
@@ -753,7 +753,7 @@ public:
   { }
 
 protected:
-  void mouseMoveEvent( QGraphicsSceneMouseEvent* event ) { }
+  void mouseMoveEvent(QGraphicsSceneMouseEvent* /* event */) {}
 
   void mousePressEvent( QGraphicsSceneMouseEvent* event )
   {
@@ -778,7 +778,7 @@ protected:
         CGAL::make_x_monotone( arc, std::back_inserter( subarcs ) );
         typename CircularKernel::Has_on_2 has_on;
         bool isOn = false;
-        for ( int i = 0; i < subarcs.size( ); ++i )
+        for ( unsigned int i = 0; i < subarcs.size( ); ++i )
         {
           Circular_arc_2 subarc;
           if ( CGAL::assign( subarc, subarcs[ i ] ) )
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/PointLocationCallback.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/PointLocationCallback.h
index c56d815a3ae..26245c5a327 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/PointLocationCallback.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/PointLocationCallback.h
@@ -148,7 +148,7 @@ mousePressEvent( QGraphicsSceneMouseEvent* event )
 
 template < typename Arr_ >
 void PointLocationCallback< Arr_ >::
-mouseMoveEvent( QGraphicsSceneMouseEvent* event )
+mouseMoveEvent(QGraphicsSceneMouseEvent* /* event */)
 { }
 
 template < typename Arr_ >
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/SplitEdgeCallback.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/SplitEdgeCallback.h
index 1474ca56d9b..69ba570ef5e 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/SplitEdgeCallback.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/SplitEdgeCallback.h
@@ -25,8 +25,9 @@
 #include <QGraphicsScene>
 #include <QGraphicsSceneMouseEvent>
 #include <CGAL/Qt/Converter.h>
-#include "CurveGraphicsItem.h"
 #include <CGAL/Arrangement_with_history_2.h>
+
+#include "CurveGraphicsItem.h"
 #include "Utils.h"
 #include "ISnappable.h"
 
@@ -239,18 +240,17 @@ splitEdges( const Point_2& clickedPoint, TTraits traits )
 template < typename Arr_ >
 template < typename CircularKernel >
 void SplitEdgeCallback< Arr_ >::
-splitEdges( const Point_2& clickedPoint,
-            CGAL::Arr_circular_arc_traits_2< CircularKernel > traits )
+splitEdges(const Point_2& /* clickedPoint */,
+           CGAL::Arr_circular_arc_traits_2< CircularKernel > /* traits */)
 {
   // std::cout << "Circular arc split edges stub" << std::endl;
 }
 
 template < typename Arr_ >
 template < typename Coefficient_ >
-void
-SplitEdgeCallback< Arr_ >::
-splitEdges( const Point_2& clickedPoint,
-            CGAL::Arr_algebraic_segment_traits_2< Coefficient_ > traits )
+void SplitEdgeCallback< Arr_ >::
+splitEdges(const Point_2& /* clickedPoint */,
+           CGAL::Arr_algebraic_segment_traits_2< Coefficient_ > /* traits */)
 {
   // std::cout << "Algebraic segment split edges stub" << std::endl;
 }
@@ -265,8 +265,8 @@ SplitEdgeCallback< Arr_ >::mouseMoveEvent( QGraphicsSceneMouseEvent* event )
 
 template < typename Arr_ >
 template < typename TTraits >
-void SplitEdgeCallback< Arr_ >::updateGuide( const Point_2& clickedPoint,
-                                             TTraits traits )
+void SplitEdgeCallback<Arr_>::updateGuide(const Point_2& clickedPoint,
+                                          TTraits /* traits */)
 {
   if ( this->hasFirstPoint )
   { // provide visual feedback for where the split line is
@@ -285,8 +285,8 @@ void SplitEdgeCallback< Arr_ >::updateGuide( const Point_2& clickedPoint,
 template < typename Arr_ >
 template < typename CircularKernel >
 void SplitEdgeCallback< Arr_ >::
-updateGuide( const Point_2& clickedPoint,
-             CGAL::Arr_circular_arc_traits_2< CircularKernel > traits )
+updateGuide(const Point_2& clickedPoint,
+            CGAL::Arr_circular_arc_traits_2< CircularKernel > /* traits */)
 {
   if ( this->hasFirstPoint )
   { // provide visual feedback for where the split line is
@@ -312,8 +312,8 @@ SplitEdgeCallback< Arr_ >::snapPoint( QGraphicsSceneMouseEvent* event )
 template < typename Arr_ >
 template < typename TTraits >
 typename SplitEdgeCallback< Arr_ >::Point_2
-SplitEdgeCallback< Arr_ >::snapPoint( QGraphicsSceneMouseEvent *event,
-                                      TTraits traits )
+SplitEdgeCallback<Arr_>::snapPoint(QGraphicsSceneMouseEvent* event,
+                                   TTraits /* traits */)
 {
   if ( this->snapToGridEnabled )
   {
@@ -335,8 +335,8 @@ SplitEdgeCallback< Arr_ >::snapPoint( QGraphicsSceneMouseEvent *event,
 template < typename Arr_ >
 template < typename CircularKernel >
 typename SplitEdgeCallback< Arr_ >::Point_2 SplitEdgeCallback< Arr_ >::
-snapPoint( QGraphicsSceneMouseEvent* event,
-           CGAL::Arr_circular_arc_traits_2< CircularKernel > traits )
+snapPoint(QGraphicsSceneMouseEvent* event,
+          CGAL::Arr_circular_arc_traits_2<CircularKernel> /* traits */)
 {
   if ( this->snapToGridEnabled )
   {
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/Utils.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/Utils.h
index f21597e619b..4140aa76888 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/Utils.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/Utils.h
@@ -414,10 +414,10 @@ public: // methods
   double operator() ( const Point_2& p, const X_monotone_curve_2& c ) const
   {
     // Get the co-ordinates of the curve's source and target.
-    double sx = CGAL::to_double( c.source( ).x( ) ),
-      sy = CGAL::to_double( c.source( ).y( ) ),
-      tx = CGAL::to_double( c.target( ).x( ) ),
-      ty = CGAL::to_double( c.target( ).y( ) );
+    // double sx = CGAL::to_double( c.source( ).x( ) );
+    // double sy = CGAL::to_double( c.source( ).y( ) );
+    // double tx = CGAL::to_double( c.target( ).x( ) );
+    // double ty = CGAL::to_double( c.target( ).y( ) );
 
     if ( c.orientation( ) == CGAL::COLLINEAR )
     {
@@ -432,7 +432,7 @@ public: // methods
     {
       // If the curve is monotone, than its source and its target has the
       // extreme x co-ordinates on this curve.
-      bool is_source_left = (sx < tx);
+      // bool is_source_left = (sx < tx);
       //int  x_min = is_source_left ? (*w).x_pixel(sx) : (*w).x_pixel(tx);
       //int  x_max = is_source_left ? (*w).x_pixel(tx) : (*w).x_pixel(sx);
       //double   prev_x = is_source_left ? sx : tx;
@@ -443,7 +443,7 @@ public: // methods
 
       bool first = true;
       FT min_dist( 100000000 );
-      AlgKernel ker;
+      // AlgKernel ker;
 
       int n = 100;
       if ( this->scene != NULL && this->scene->views( ).size( ) != 0 )
@@ -501,7 +501,8 @@ public:
   typedef typename Traits::X_monotone_curve_2 X_monotone_curve_2;
 
 public:
-  double operator() ( const Point_2& p, const X_monotone_curve_2& c ) const
+  double operator()(const Point_2& /* p */,
+                    const X_monotone_curve_2& /* c */) const
   {
     double res = 0.0;
     return res;
@@ -515,14 +516,14 @@ public:
   typedef ArrTraits Traits;
   typedef typename ArrTraitsAdaptor< Traits >::Kernel   Kernel;
   typedef typename ArrTraitsAdaptor< Traits >::CoordinateType CoordinateType;
-  //typedef typename Kernel::FT FT;
+  // typedef typename Kernel::FT FT;
   typedef typename Kernel::Point_2                      Point_2;
   typedef typename Kernel::Line_2                       Line_2;
   typedef typename Traits::X_monotone_curve_2           X_monotone_curve_2;
   typedef typename Traits::Multiplicity                 Multiplicity;
   typedef typename Traits::Intersect_2                  Intersect_2;
   typedef std::pair< typename Traits::Point_2, Multiplicity >
-    IntersectionResult;
+                                                        IntersectionResult;
 
   Arr_compute_y_at_x_2( ):
     intersectCurves( this->traits.intersect_2_object( ) )
@@ -580,7 +581,7 @@ protected:
     typename TTraits::Construct_x_monotone_curve_2 construct_x_monotone_curve_2 =
       traits_.construct_x_monotone_curve_2_object( );
     CoordinateType res( 0 );
-    QRectF clipRect = this->viewportRect( );
+    // QRectF clipRect = this->viewportRect( );
     Line_2 line = curve.supporting_line( );
     // FIXME: get a better bounding box for an unbounded segment
     Point_2 p1c1( x, CoordinateType( -10000000 ) ); // clicked point
@@ -956,7 +957,8 @@ public: // typedefs
   typedef typename Kernel::Segment_2 Segment_2;
 
 public: // methods
-  // curve can be unbounded. if curve is unbounded to the left, pLeft is a point on the left edge of viewport.
+  // curve can be unbounded. if curve is unbounded to the left,
+  // pLeft is a point on the left edge of viewport.
   X_monotone_curve_2 operator() ( const X_monotone_curve_2& curve,
                                   const Point_2& pLeft, const Point_2& pRight )
   {
@@ -1029,9 +1031,9 @@ class SnapToGridStrategy : public SnapStrategy< ArrTraits >
 {
 public:
   typedef typename ArrTraitsAdaptor< ArrTraits >::Kernel Kernel;
-  typedef typename ArrTraits::Point_2 Point_2;
-  typedef typename Kernel::Point_2 Kernel_point_2;
-  typedef SnapStrategy< ArrTraits > Superclass;
+  typedef typename ArrTraits::Point_2                   Point_2;
+  typedef typename Kernel::Point_2                      Kernel_point_2;
+  typedef SnapStrategy< ArrTraits >                     Superclass;
 
   SnapToGridStrategy( ) :
     Superclass( NULL ),
@@ -1049,7 +1051,7 @@ public:
   }
 
   template < class TTraits >
-  Point_2 snapPoint( QGraphicsSceneMouseEvent* event, TTraits traits )
+  Point_2 snapPoint(QGraphicsSceneMouseEvent* event, TTraits /* traits */)
   {
     QPointF clickedPoint = event->scenePos( );
     QRectF viewportRect = this->viewportRect( );
@@ -1092,8 +1094,8 @@ public:
   }
 
   template < class CircularKernel >
-  Point_2 snapPoint( QGraphicsSceneMouseEvent* event,
-                     CGAL::Arr_circular_arc_traits_2< CircularKernel > traits )
+  Point_2 snapPoint(QGraphicsSceneMouseEvent* event,
+                    CGAL::Arr_circular_arc_traits_2<CircularKernel> /* traits */)
   {
     QPointF clickedPoint = event->scenePos( );
     QRectF viewportRect = this->viewportRect( );
@@ -1150,7 +1152,7 @@ class SnapToArrangementVertexStrategy:
   public SnapStrategy< typename Arr_::Geometry_traits_2 >
 {
 public:
-  typedef Arr_ Arrangement;
+  typedef Arr_                                          Arrangement;
   typedef typename Arrangement::Geometry_traits_2       Traits;
   typedef typename ArrTraitsAdaptor< Traits >::Kernel   Kernel;
   typedef SnapStrategy< Traits >                        Superclass;
@@ -1178,7 +1180,7 @@ public:
   }
 
   template < class TTraits >
-  Point_2 snapPoint( const Kernel_point_2& clickedPoint, TTraits traits )
+  Point_2 snapPoint(const Kernel_point_2& clickedPoint, TTraits /* traits */)
   {
     Point_2 initialPoint( CGAL::to_double(clickedPoint.x()),
                           CGAL::to_double(clickedPoint.y()) );
@@ -1218,8 +1220,8 @@ public:
   }
 
   template < class CircularKernel >
-  Point_2 snapPoint( const Kernel_point_2& clickedPoint,
-                     CGAL::Arr_circular_arc_traits_2< CircularKernel > traits )
+  Point_2 snapPoint(const Kernel_point_2& clickedPoint,
+                    CGAL::Arr_circular_arc_traits_2<CircularKernel> /* traits */)
   {
     typedef Kernel_point_2 Non_arc_point_2;
     typedef typename CircularKernel::Circular_arc_point_2 Arc_point_2;
@@ -1298,7 +1300,7 @@ public:
 
 protected:
   template < class T, class TTraits >
-  Point_2 operator()( const T& x, const T& y, TTraits traits )
+  Point_2 operator()(const T& x, const T& y, TTraits /* traits */)
   {
     CoordinateType xx( x );
     CoordinateType yy( y );
@@ -1307,8 +1309,9 @@ protected:
   }
 
   template < class T, class CircularKernel >
-  Point_2 operator()( const T& x, const T& y,
-                      CGAL::Arr_circular_arc_traits_2< CircularKernel > traits )
+  Point_2 operator()(const T& x, const T& y,
+                     CGAL::Arr_circular_arc_traits_2<CircularKernel>
+                     /* traits */)
   {
     typedef typename CircularKernel::Root_for_circles_2_2 Root_for_circles_2_2;
     CoordinateType xx( x );
@@ -1335,7 +1338,7 @@ public: // typedefs
   typedef Compute_squared_distance_2< ArrTraits > Point_curve_distance;
   typedef typename ArrTraits::X_monotone_curve_2 X_monotone_curve_2;
   typedef CGAL::Arr_walk_along_line_point_location< Arrangement >
-    Point_location_strategy;
+                                                        Point_location_strategy;
   typedef typename ArrTraitsAdaptor< ArrTraits >::Kernel Kernel;
   typedef typename Kernel::Point_2                      Point_2;
   typedef typename Arrangement::Face_const_handle       Face_const_handle;
@@ -1343,7 +1346,7 @@ public: // typedefs
   typedef typename Arrangement::Vertex_const_handle     Vertex_const_handle;
   typedef typename Arrangement::Ccb_halfedge_const_circulator
     Ccb_halfedge_const_circulator;
-  typedef typename Point_curve_distance::FT FT;
+  typedef typename Point_curve_distance::FT             FT;
   typedef typename Arrangement::Hole_const_iterator     Hole_const_iterator;
   typedef typename Arrangement::Halfedge_around_vertex_const_circulator
     Halfedge_around_vertex_const_circulator;
@@ -1407,7 +1410,7 @@ public: // member methods
 #endif
     Hole_const_iterator hit; 
     Hole_const_iterator eit = face->holes_end( );
-    int counter = 0;
+    // int counter = 0;
     for ( hit = face->holes_begin( ); hit != eit; ++hit )
     { // check any holes inside this face
       Ccb_halfedge_const_circulator cc = *hit;
@@ -1465,18 +1468,18 @@ protected: // member fields
 
 #if 0
 template < class Arr_, class Coefficient_ >
-class Find_nearest_edge< Arr_, CGAL::Arr_algebraic_segment_traits_2< Coefficient_ > >: public Find_nearest_edge_base
+class Find_nearest_edge< Arr_, CGAL::Arr_algebraic_segment_traits_2<
+                                 Coefficient_ > >: public Find_nearest_edge_base
 {
 public:
   Halfedge_const_handle operator()( const Point_2& queryPt )
-  {
-
-  }
+  { }
 };
 #endif
 
 template < class Arr_, class Kernel_ >
-class Find_nearest_edge< Arr_, CGAL::Arr_linear_traits_2< Kernel_ > >: public Find_nearest_edge_base
+class Find_nearest_edge< Arr_, CGAL::Arr_linear_traits_2< Kernel_ > > :
+  public Find_nearest_edge_base
 {
 public: // typedefs
   typedef Arr_ Arrangement;
@@ -1484,15 +1487,15 @@ public: // typedefs
   typedef Compute_squared_distance_2< ArrTraits >       Point_curve_distance;
   typedef typename ArrTraits::X_monotone_curve_2        X_monotone_curve_2;
   typedef CGAL::Arr_walk_along_line_point_location< Arrangement >
-    Point_location_strategy;
+                                                        Point_location_strategy;
   typedef typename ArrTraitsAdaptor< ArrTraits >::Kernel Kernel;
-  typedef typename Kernel::Point_2 Point_2;
+  typedef typename Kernel::Point_2                      Point_2;
   typedef typename Arrangement::Face_const_handle       Face_const_handle;
   typedef typename Arrangement::Halfedge_const_handle   Halfedge_const_handle;
   typedef typename Arrangement::Vertex_const_handle     Vertex_const_handle;
   typedef typename Arrangement::Ccb_halfedge_const_circulator
     Ccb_halfedge_const_circulator;
-  typedef typename Point_curve_distance::FT FT;
+  typedef typename Point_curve_distance::FT             FT;
   typedef typename Arrangement::Hole_const_iterator     Hole_const_iterator;
   typedef typename Arrangement::Halfedge_around_vertex_const_circulator
     Halfedge_around_vertex_const_circulator;
diff --git a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/VerticalRayShootCallback.h b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/VerticalRayShootCallback.h
index 962249704f0..e34ab4e9303 100644
--- a/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/VerticalRayShootCallback.h
+++ b/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/VerticalRayShootCallback.h
@@ -211,7 +211,7 @@ mousePressEvent( QGraphicsSceneMouseEvent* event )
 
 template < typename Arr_ >
 void VerticalRayShootCallback< Arr_ >::
-mouseMoveEvent( QGraphicsSceneMouseEvent* event )
+mouseMoveEvent(QGraphicsSceneMouseEvent* /* event */)
 { }
 
 template < typename Arr_ >
@@ -251,8 +251,8 @@ highlightPointLocation( QGraphicsSceneMouseEvent* event )
   {
     Kernel_point_2 p2( FT( this->queryPt.x( ) ), y2 );
     Segment_2 lineSegment( this->queryPt, p2 );
-    QLineF qLineSegment = this->convert( lineSegment );
-    //this->activeRay->setLine( qLineSegment );
+    // QLineF qLineSegment = this->convert( lineSegment );
+    // this->activeRay->setLine( qLineSegment );
     this->rayGraphicsItem.setSource( event->scenePos( ) );
     this->rayGraphicsItem.setTargetY( CGAL::to_double( y2 ) );
     this->rayGraphicsItem.setIsInfinite( true );
@@ -270,8 +270,8 @@ highlightPointLocation( QGraphicsSceneMouseEvent* event )
     FT yInt( yApprox );
     Kernel_point_2 p2( this->queryPt.x( ), yInt );
     Segment_2 seg( this->queryPt, p2 );
-    QLineF qseg = this->convert( seg );
-    //this->activeRay->setLine( qseg );
+    // QLineF qseg = this->convert( seg );
+    // this->activeRay->setLine( qseg );
     this->rayGraphicsItem.setSource( event->scenePos( ) );
     this->rayGraphicsItem.setTargetY( CGAL::to_double( yInt ) );
     this->rayGraphicsItem.setIsInfinite( false );