[#773 FIX] remove unused variable warning

using fancy c++17 feature

src/qtgui/controlPanel/transferFunction2D/WTransferFunction2DGUIWidget.cpp

@@ -305,7 +305,10 @@ void WTransferFunction2DGUIWidget::insertWidget(  Shapes shape,
     dataChanged();
 }
 
-void WTransferFunction2DGUIWidget::updateWidget( Shapes shape, std::vector<QPointF> points, const QColor * const color, const QPointF &pos )
+void WTransferFunction2DGUIWidget::updateWidget( Shapes shape,
+                                                 std::vector<QPointF> points,
+                                                 const QColor * const color,
+                                                 [[maybe_unused]] const QPointF &pos )
 {
     WTransferFunction2DShapeWidget *newShapeWidget( new WTransferFunction2DShapeWidget( this, shape, *color, points ) );
     scene->addItem( newShapeWidget );

src/qtgui/controlPanel/transferFunction2D/WTransferFunction2DGUIWidget.h

@@ -128,7 +128,7 @@ public:
      * @param color 
      * @param pos
      */
-    void updateWidget( Shapes shape, std::vector<QPointF> points, const QColor * const color, const QPointF &pos );
+    void updateWidget( Shapes shape, std::vector<QPointF> points, const QColor * const color, [[maybe_unused]] const QPointF &pos );
 
     /**
      * @brief Get the pointer to the Animator connected to the 2DTF