Gui: Compiler warning cleanup

src/Gui/DAGView/DAGModel.cpp

@@ -496,9 +496,6 @@ void Model::updateSlot()
     // sync scene items for graph edge.
     BGL_FORALL_EDGES(currentEdge, *theGraph, Graph)
     {
-        Vertex source = boost::source(currentEdge, *theGraph);
-        Vertex target = boost::target(currentEdge, *theGraph);
-
         if (!(*theGraph)[currentEdge].connector->scene()) {
             this->addItem((*theGraph)[currentEdge].connector.get());
         }

src/Gui/Dialogs/DlgExpressionInput.cpp

@@ -1058,7 +1058,8 @@ void DlgExpressionInput::setMsgText()
     // elide text if it is going out of widget bounds
     // note: this is only 'rough elide', as this text is usually not very long;
     const int msgLinesLimit = 3;
-    if (wrappedMsg.size() > msgContentWidth / msgFontMetrics.averageCharWidth() * msgLinesLimit) {
+    if (static_cast<int>(wrappedMsg.size())
+        > msgContentWidth / msgFontMetrics.averageCharWidth() * msgLinesLimit) {
         const QString elidedMsg = msgFontMetrics.elidedText(
             QString::fromStdString(wrappedMsg),
             Qt::ElideRight,

src/Gui/Dialogs/DlgThemeEditor.h

@@ -94,7 +94,7 @@ public:
     std::optional<StyleParameters::Parameter> get(const std::string& name) const override;
 
     void reset();
-    void flush();
+    void flush() override;
 
     int rowCount(const QModelIndex& index) const override;
     int columnCount(const QModelIndex& index) const override;