Fix dev warning.

include/ftxui/dom/selection.hpp

@@ -31,13 +31,13 @@ class Selection {
  private:
   Selection(int start_x, int start_y, int end_x, int end_y, Selection* parent);
 
-  Selection* const parent_ = this;
-  const bool empty_ = true;
   const int start_x_ = 0;
   const int start_y_ = 0;
   const int end_x_ = 0;
   const int end_y_ = 0;
   const Box box_ = {};
+  Selection* const parent_ = this;
+  const bool empty_ = true;
   std::stringstream parts_;
 
   // The position of the last inserted part.

src/ftxui/dom/flexbox.cpp

@@ -206,7 +206,8 @@ class Flexbox : public Node {
           IsColumnOriented() ? selection_lines.SaturateHorizontal(box)
                              : selection_lines.SaturateVertical(box);
 
-      for (auto& block : line.blocks) {
+      for (auto& _: line.blocks) {
+        std::ignore = _;
         children_[i]->Select(selection_line);
         i++;
       }

src/ftxui/dom/selection.cpp

@@ -15,7 +15,7 @@ class Unselectable : public NodeDecorator {
  public:
   using NodeDecorator::NodeDecorator;
 
-  void Select(Selection& selection) override {
+  void Select(Selection&) override {
     // Overwrite the select method to do nothing.
   }
 };

src/ftxui/dom/selection_style.cpp

@@ -20,7 +20,7 @@ class SelectionStyleReset : public NodeDecorator {
 
   void Render(Screen& screen) final {
     auto old_style = screen.GetSelectionStyle();
-    screen.SetSelectionStyle([](Pixel& pixel) {});
+    screen.SetSelectionStyle([](Pixel&) {});
     NodeDecorator::Render(screen);
     screen.SetSelectionStyle(old_style);
   }

src/ftxui/dom/text.cpp

@@ -88,7 +88,6 @@ class Text : public Node {
   bool has_selection = false;
   int selection_start_ = 0;
   int selection_end_ = -1;
-  std::function<void(Pixel& pixel)> selectionTransform;
 };
 
 class VText : public Node {