Remove explicit default destructors (#157)

From CppCoreGuidelines:

Rule of Zero: C.20: If you can avoid defining default operations, do.
C.52: Use inheriting constructors to import constructors into a derived class that does not need further explicit initialization.
DRY forward and using declarations.
Miscellaneous:

Fix format.sh to output examples with normalised paths in sorted order.

Co-authored-by: ArthurSonzogni <sonzogniarthur@gmail.com>

doc/example_list.md

@@ -1,46 +1,46 @@
 # Examples
-@example ./examples/util/print_key_press.cpp
-@example ./examples/dom/color_truecolor_HSV.cpp
-@example ./examples/dom/dbox.cpp
-@example ./examples/dom/separator.cpp
-@example ./examples/dom/style_color.cpp
-@example ./examples/dom/color_info_palette256.cpp
-@example ./examples/dom/color_truecolor_RGB.cpp
-@example ./examples/dom/paragraph.cpp
-@example ./examples/dom/style_blink.cpp
-@example ./examples/dom/style_dim.cpp
-@example ./examples/dom/style_inverted.cpp
-@example ./examples/dom/graph.cpp
-@example ./examples/dom/package_manager.cpp
-@example ./examples/dom/window.cpp
-@example ./examples/dom/html_like.cpp
-@example ./examples/dom/border.cpp
-@example ./examples/dom/style_underlined.cpp
-@example ./examples/dom/color_gallery.cpp
-@example ./examples/dom/gauge.cpp
-@example ./examples/dom/style_bold.cpp
-@example ./examples/dom/spinner.cpp
-@example ./examples/dom/style_gallery.cpp
-@example ./examples/dom/vbox_hbox.cpp
-@example ./examples/dom/size.cpp
-@example ./examples/dom/hflow.cpp
-@example ./examples/component/tab_vertical.cpp
-@example ./examples/component/gallery.cpp
+@example ./examples/component/button.cpp
 @example ./examples/component/checkbox.cpp
 @example ./examples/component/checkbox_in_frame.cpp
-@example ./examples/component/menu2.cpp
-@example ./examples/component/resizable_split.cpp
-@example ./examples/component/tab_horizontal.cpp
-@example ./examples/component/slider.cpp
-@example ./examples/component/input.cpp
-@example ./examples/component/homescreen.cpp
-@example ./examples/component/radiobox.cpp
-@example ./examples/component/menu_multiple.cpp
-@example ./examples/component/slider_rgb.cpp
-@example ./examples/component/menu.cpp
-@example ./examples/component/menu_style.cpp
-@example ./examples/component/radiobox_in_frame.cpp
 @example ./examples/component/composition.cpp
-@example ./examples/component/button.cpp
-@example ./examples/component/toggle.cpp
+@example ./examples/component/gallery.cpp
+@example ./examples/component/homescreen.cpp
+@example ./examples/component/input.cpp
+@example ./examples/component/menu2.cpp
+@example ./examples/component/menu.cpp
+@example ./examples/component/menu_multiple.cpp
+@example ./examples/component/menu_style.cpp
 @example ./examples/component/modal_dialog.cpp
+@example ./examples/component/radiobox.cpp
+@example ./examples/component/radiobox_in_frame.cpp
+@example ./examples/component/resizable_split.cpp
+@example ./examples/component/slider.cpp
+@example ./examples/component/slider_rgb.cpp
+@example ./examples/component/tab_horizontal.cpp
+@example ./examples/component/tab_vertical.cpp
+@example ./examples/component/toggle.cpp
+@example ./examples/dom/border.cpp
+@example ./examples/dom/color_gallery.cpp
+@example ./examples/dom/color_info_palette256.cpp
+@example ./examples/dom/color_truecolor_HSV.cpp
+@example ./examples/dom/color_truecolor_RGB.cpp
+@example ./examples/dom/dbox.cpp
+@example ./examples/dom/gauge.cpp
+@example ./examples/dom/graph.cpp
+@example ./examples/dom/hflow.cpp
+@example ./examples/dom/html_like.cpp
+@example ./examples/dom/package_manager.cpp
+@example ./examples/dom/paragraph.cpp
+@example ./examples/dom/separator.cpp
+@example ./examples/dom/size.cpp
+@example ./examples/dom/spinner.cpp
+@example ./examples/dom/style_blink.cpp
+@example ./examples/dom/style_bold.cpp
+@example ./examples/dom/style_color.cpp
+@example ./examples/dom/style_dim.cpp
+@example ./examples/dom/style_gallery.cpp
+@example ./examples/dom/style_inverted.cpp
+@example ./examples/dom/style_underlined.cpp
+@example ./examples/dom/vbox_hbox.cpp
+@example ./examples/dom/window.cpp
+@example ./examples/util/print_key_press.cpp

include/ftxui/component/captured_mouse.hpp

@@ -6,7 +6,7 @@
 namespace ftxui {
 class CapturedMouseInterface {
  public:
-  virtual ~CapturedMouseInterface() {}
+  virtual ~CapturedMouseInterface() = default;
 };
 using CapturedMouse = std::unique_ptr<CapturedMouseInterface>;
 }  // namespace ftxui

include/ftxui/component/component.hpp

@@ -2,29 +2,24 @@
 #define FTXUI_COMPONENT_HPP
 
 #include <functional>  // for function
-#include <memory>      // for shared_ptr, make_shared
+#include <memory>      // for make_shared, shared_ptr
 #include <string>      // for wstring
 #include <vector>      // for vector
 
-#include "ftxui/component/component_base.hpp"
-#include "ftxui/component/component_options.hpp"
+#include "ftxui/component/component_base.hpp"     // for Component, Components
+#include "ftxui/component/component_options.hpp"  // for ButtonOption, CheckboxOption, InputOption, MenuOption, RadioboxOption, ToggleOption
 #include "ftxui/dom/elements.hpp"                 // for Element
 #include "ftxui/util/ref.hpp"  // for Ref, ConstStringRef, StringRef
 
 namespace ftxui {
-
-class ComponentBase;
-struct Event;
 struct ButtonOption;
 struct CheckboxOption;
+struct Event;
 struct InputOption;
 struct MenuOption;
 struct RadioboxOption;
 struct ToggleOption;
 
-using Component = std::shared_ptr<ComponentBase>;
-using Components = std::vector<Component>;
-
 template <class T, class... Args>
 std::shared_ptr<T> Make(Args&&... args) {
   return std::make_shared<T>(args...);

include/ftxui/component/component_base.hpp

@@ -22,8 +22,7 @@ using Components = std::vector<Component>;
 /// @ingroup component
 class ComponentBase {
  public:
-  // Constructor/Destructor.
-  ComponentBase() = default;
+  // virtual Destructor.
   virtual ~ComponentBase();
 
   // Component hierarchy:
@@ -73,8 +72,6 @@ class ComponentBase {
   ComponentBase* parent_ = nullptr;
 };
 
-using Component = std::shared_ptr<ComponentBase>;
-
 }  // namespace ftxui
 
 #endif /* end of include guard: FTXUI_COMPONENT_BASE_HPP */

include/ftxui/component/screen_interactive.hpp

@@ -8,14 +8,14 @@
 #include <string>                        // for string
 
 #include "ftxui/component/captured_mouse.hpp"  // for CapturedMouse
-#include "ftxui/component/event.hpp"
+#include "ftxui/component/event.hpp"           // for Event
 #include "ftxui/screen/screen.hpp"             // for Screen
 
 namespace ftxui {
 class ComponentBase;
+struct Event;
 
 using Component = std::shared_ptr<ComponentBase>;
-struct Event;
 
 class ScreenInteractive : public Screen {
  public:

include/ftxui/dom/node.hpp

@@ -14,7 +14,7 @@ class Node;
 class Screen;
 
 using Element = std::shared_ptr<Node>;
-using Elements = std::vector<std::shared_ptr<Node>>;
+using Elements = std::vector<Element>;
 
 class Node {
  public:

include/ftxui/screen/screen.hpp

@@ -10,9 +10,6 @@
 
 namespace ftxui {
 class Node;
-}
-
-namespace ftxui {
 using Element = std::shared_ptr<Node>;
 
 /// @brief A unicode character and its associated style.

src/ftxui/component/button.cpp

@@ -23,8 +23,6 @@ class ButtonBase : public ComponentBase {
              Ref<ButtonOption> option)
       : label_(label), on_click_(on_click), option_(std::move(option)) {}
 
-  ~ButtonBase() override = default;
-
   // Component implementation:
   Element Render() override {
     auto style = Focused() ? inverted : nothing;

src/ftxui/component/catch_event.cpp

@@ -13,7 +13,6 @@ class CatchEventBase : public ComponentBase {
   // Constructor.
   CatchEventBase(std::function<bool(Event)> on_event)
       : on_event_(std::move(on_event)) {}
-  ~CatchEventBase() override = default;
 
   // Component implementation.
   bool OnEvent(Event event) override {

src/ftxui/component/checkbox.cpp

@@ -29,8 +29,6 @@ class CheckboxBase : public ComponentBase {
 #endif
   }
 
-  ~CheckboxBase() override = default;
-
  private:
   // Component implementation.
   Element Render() override {

src/ftxui/component/component.cpp

@@ -14,10 +14,7 @@
 namespace ftxui {
 
 namespace {
-class CaptureMouseImpl : public CapturedMouseInterface {
- public:
-  ~CaptureMouseImpl() override {}
-};
+class CaptureMouseImpl : public CapturedMouseInterface {};
 }  // namespace
 
 ComponentBase::~ComponentBase() {
@@ -161,9 +158,9 @@ void ComponentBase::TakeFocus() {
 /// @param event
 /// @ingroup component
 CapturedMouse ComponentBase::CaptureMouse(const Event& event) {
-  if (!event.screen_)
-    return std::make_unique<CaptureMouseImpl>();
+  if (event.screen_)
     return event.screen_->CaptureMouse();
+  return std::make_unique<CaptureMouseImpl>();
 }
 
 }  // namespace ftxui

src/ftxui/component/container.cpp

@@ -53,8 +53,6 @@ class ContainerBase : public ComponentBase {
     return container;
   }
 
-  ~ContainerBase() override = default;
-
   // Component override.
   bool OnEvent(Event event) override {
     if (event.is_mouse())

src/ftxui/component/input.cpp

@@ -24,7 +24,6 @@ class InputBase : public ComponentBase {
             ConstStringRef placeholder,
             Ref<InputOption> option)
       : content_(content), placeholder_(placeholder), option_(option) {}
-  ~InputBase() override = default;
 
   int& cursor_position() { return *(option_->cursor_position); }
 

src/ftxui/component/radiobox.cpp

@@ -38,7 +38,6 @@ class RadioboxBase : public ComponentBase {
       option_->style_unchecked = L"( )";
 #endif
   }
-  ~RadioboxBase() override = default;
 
  private:
   Element Render() override {

src/ftxui/component/renderer.cpp

@@ -18,7 +18,6 @@ class RendererBase : public ComponentBase {
 
   // Constructor.
   RendererBase(std::function<Element()> render) : render_(std::move(render)) {}
-  ~RendererBase() override = default;
 
   // Component implementation.
   Element Render() override { return render_(); }

src/ftxui/component/toggle.cpp

@@ -29,8 +29,6 @@ class ToggleBase : public ComponentBase {
              Ref<ToggleOption> option)
       : entries_(entries), selected_(selected), option_(std::move(option)) {}
 
-  ~ToggleBase() override = default;
-
  private:
   Element Render() override {
     Elements children;

src/ftxui/dom/blink.cpp

@@ -11,8 +11,7 @@ namespace ftxui {
 
 class Blink : public NodeDecorator {
  public:
-  Blink(Elements children) : NodeDecorator(std::move(children)) {}
-  ~Blink() override {}
+  using NodeDecorator::NodeDecorator;
 
   void Render(Screen& screen) override {
     Node::Render(screen);

src/ftxui/dom/bold.cpp

@@ -11,8 +11,7 @@ namespace ftxui {
 
 class Bold : public NodeDecorator {
  public:
-  Bold(Elements children) : NodeDecorator(std::move(children)) {}
-  ~Bold() override {}
+  using NodeDecorator::NodeDecorator;
 
   void Render(Screen& screen) override {
     for (int y = box_.y_min; y <= box_.y_max; ++y) {

src/ftxui/dom/border.cpp

@@ -22,7 +22,6 @@ class Border : public Node {
                 std::end(simple_border_charset)) {}
   Border(Elements children, Pixel pixel)
       : Node(std::move(children)), charset_pixel(10, pixel) {}
-  ~Border() override {}
 
   std::vector<Pixel> charset_pixel;
   std::vector<wchar_t> charset;

src/ftxui/dom/clear_under.cpp

@@ -13,8 +13,7 @@ using ftxui::Screen;
 
 class ClearUnder : public NodeDecorator {
  public:
-  ClearUnder(Elements children) : NodeDecorator(std::move(children)) {}
-  ~ClearUnder() override {}
+  using NodeDecorator::NodeDecorator;
 
   void Render(Screen& screen) override {
     for (int y = box_.y_min; y <= box_.y_max; ++y) {

src/ftxui/dom/color.cpp

@@ -30,7 +30,6 @@ class FgColor : public NodeDecorator {
  public:
   FgColor(Elements children, Color color)
       : NodeDecorator(std::move(children)), color_(color) {}
-  ~FgColor() override {}
 
   void Render(Screen& screen) override {
     for (int y = box_.y_min; y <= box_.y_max; ++y) {

src/ftxui/dom/dbox.cpp

@@ -13,7 +13,6 @@ namespace ftxui {
 class DBox : public Node {
  public:
   DBox(Elements children) : Node(std::move(children)) {}
-  ~DBox() {}
 
   void ComputeRequirement() override {
     requirement_.min_x = 0;

src/ftxui/dom/dim.cpp

@@ -9,12 +9,9 @@
 
 namespace ftxui {
 
-using ftxui::Screen;
-
 class Dim : public NodeDecorator {
  public:
-  Dim(Elements children) : NodeDecorator(std::move(children)) {}
-  ~Dim() override {}
+  using NodeDecorator::NodeDecorator;
 
   void Render(Screen& screen) override {
     Node::Render(screen);

src/ftxui/dom/flex.cpp

@@ -67,9 +67,8 @@ void function_not_flex(Requirement& r) {
 
 class Flex : public Node {
  public:
-  Flex(FlexFunction f) { f_ = f; }
+  Flex(FlexFunction f) : f_(f) {}
   Flex(FlexFunction f, Element child) : Node(unpack(std::move(child))), f_(f) {}
-  ~Flex() override {}
   void ComputeRequirement() override {
     requirement_.min_x = 0;
     requirement_.min_y = 0;

src/ftxui/dom/gauge.cpp

@@ -19,7 +19,6 @@ static wchar_t charset[] = L"  ▏▎▍▌▋▊▉█";
 class Gauge : public Node {
  public:
   Gauge(float progress) : progress_(progress) {}
-  ~Gauge() override {}
 
   void ComputeRequirement() override {
     requirement_.flex_grow_x = 1;

src/ftxui/dom/graph.cpp

@@ -21,7 +21,6 @@ const wchar_t charset[] = L" ▗▐▖▄▟▌▙█";
 class Graph : public Node {
  public:
   Graph(GraphFunction graph_function) : graph_function_(graph_function) {}
-  ~Graph() override {}
 
   void ComputeRequirement() override {
     requirement_.flex_grow_x = 1;

src/ftxui/dom/hbox.cpp

@@ -13,7 +13,6 @@ namespace ftxui {
 class HBox : public Node {
  public:
   HBox(Elements children) : Node(std::move(children)) {}
-  ~HBox() {}
 
   void ComputeRequirement() override {
     requirement_.min_x = 0;

src/ftxui/dom/hflow.cpp

@@ -13,7 +13,6 @@ namespace ftxui {
 class HFlow : public Node {
  public:
   HFlow(Elements children) : Node(std::move(children)) {}
-  ~HFlow() {}
 
   void ComputeRequirement() override {
     requirement_.min_x = 1;

src/ftxui/dom/inverted.cpp

@@ -9,12 +9,9 @@
 
 namespace ftxui {
 
-using ftxui::Screen;
-
 class Inverted : public NodeDecorator {
  public:
-  Inverted(Elements children) : NodeDecorator(std::move(children)) {}
-  ~Inverted() override {}
+  using NodeDecorator::NodeDecorator;
 
   void Render(Screen& screen) override {
     Node::Render(screen);

src/ftxui/dom/node.cpp

@@ -5,8 +5,6 @@
 
 namespace ftxui {
 
-using ftxui::Screen;
-
 Node::Node() {}
 Node::Node(Elements children) : children_(std::move(children)) {}
 Node::~Node() {}

src/ftxui/dom/node_decorator.hpp

@@ -12,7 +12,6 @@ struct Box;
 class NodeDecorator : public Node {
  public:
   NodeDecorator(Elements children) : Node(std::move(children)) {}
-  ~NodeDecorator() override {}
   void ComputeRequirement() override;
   void SetBox(Box box) override;
 };

src/ftxui/dom/reflect.cpp

@@ -14,7 +14,6 @@ class Reflect : public Node {
  public:
   Reflect(Element child, Box& box)
       : Node(unpack(std::move(child))), reflected_box_(box) {}
-  ~Reflect() override {}
 
   void ComputeRequirement() final {
     Node::ComputeRequirement();

src/ftxui/dom/separator.cpp

@@ -13,8 +13,6 @@ using ftxui::Screen;
 
 class Separator : public Node {
  public:
-  Separator() {}
-  ~Separator() override {}
   void ComputeRequirement() override {
     requirement_.min_x = 1;
     requirement_.min_y = 1;
@@ -41,7 +39,6 @@ class Separator : public Node {
 class SeparatorWithPixel : public Separator {
  public:
   SeparatorWithPixel(Pixel pixel) : pixel_(pixel) {}
-  ~SeparatorWithPixel() override {}
   void Render(Screen& screen) override {
     for (int y = box_.y_min; y <= box_.y_max; ++y) {
       for (int x = box_.x_min; x <= box_.x_max; ++x) {

src/ftxui/dom/size.cpp

@@ -19,8 +19,6 @@ class Size : public Node {
         constraint_(constraint),
         value_(value) {}
 
-  ~Size() override {}
-
   void ComputeRequirement() override {
     Node::ComputeRequirement();
     requirement_ = children_[0]->requirement();

src/ftxui/dom/text.cpp

@@ -15,8 +15,7 @@ using ftxui::Screen;
 
 class Text : public Node {
  public:
-  Text(std::wstring text) : Node(), text_(text) {}
-  ~Text() {}
+  Text(std::wstring text) : text_(text) {}
 
   void ComputeRequirement() override {
     requirement_.min_x = wstring_width(text_);
@@ -47,11 +46,10 @@ class Text : public Node {
 
 class VText : public Node {
  public:
-  VText(std::wstring text) : Node(), text_(text) {
+  VText(std::wstring text) : text_(text) {
     for (auto& c : text_)
       width_ = std::max(width_, wchar_width(c));
   }
-  ~VText() {}
 
   void ComputeRequirement() override {
     requirement_.min_x = width_;

src/ftxui/dom/underlined.cpp

@@ -9,12 +9,9 @@
 
 namespace ftxui {
 
-using ftxui::Screen;
-
 class Underlined : public NodeDecorator {
  public:
-  Underlined(Elements children) : NodeDecorator(std::move(children)) {}
-  ~Underlined() override {}
+  using NodeDecorator::NodeDecorator;
 
   void Render(Screen& screen) override {
     Node::Render(screen);

src/ftxui/dom/vbox.cpp

@@ -13,7 +13,6 @@ namespace ftxui {
 class VBox : public Node {
  public:
   VBox(Elements children) : Node(std::move(children)) {}
-  ~VBox() {}
 
   void ComputeRequirement() override {
     requirement_.min_x = 0;

tools/format.sh

@@ -20,7 +20,7 @@ done
 
 exampleList="./doc/example_list.md"
 echo "# Examples" > $exampleList
-files=$(find ./examples/ -iname "*.cpp")
+files=$(find ./examples -iname "*.cpp" | sort)
 for f in $files
 do
   echo "@example $f" >> $exampleList