Demos: Use default constructors/destructors

https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#cother-other-default-operation-rules

"The compiler is more likely to get the default semantics right and
you cannot implement these functions better than the compiler."

Userland/Demos/Cube/Cube.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2020, Stephan Unverwerth <s.unverwerth@serenityos.org>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -31,7 +32,7 @@ static bool flag_hide_window_frame = false;
 class Cube final : public GUI::Widget {
     C_OBJECT(Cube)
 public:
-    virtual ~Cube() override;
+    virtual ~Cube() override = default;
     void set_stat_label(RefPtr<GUI::Label> l) { m_stats = l; };
     void set_show_window_frame(bool);
     bool show_window_frame() const { return m_show_window_frame; }
@@ -72,10 +73,6 @@ Cube::Cube()
     start_timer(20);
 }
 
-Cube::~Cube()
-{
-}
-
 void Cube::paint_event(GUI::PaintEvent& event)
 {
     GUI::Painter painter(*this);

Userland/Demos/Eyes/EyesWidget.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2020, Sergey Bugaev <bugaevc@serenityos.org>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -10,10 +11,6 @@
 #include <LibGUI/Window.h>
 #include <LibGfx/Palette.h>
 
-EyesWidget::~EyesWidget()
-{
-}
-
 void EyesWidget::track_mouse_move(Gfx::IntPoint const& point)
 {
     m_mouse_position = point - window()->position();

Userland/Demos/Eyes/EyesWidget.h

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2020, Sergey Bugaev <bugaevc@serenityos.org>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -14,7 +15,7 @@ class EyesWidget final : public GUI::Widget
     C_OBJECT(EyesWidget)
 
 public:
-    virtual ~EyesWidget();
+    virtual ~EyesWidget() override = default;
 
 private:
     EyesWidget(int num_eyes, int full_rows, int extra)

Userland/Demos/Fire/Fire.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -61,7 +62,7 @@ class Fire : public GUI::Frame {
     C_OBJECT(Fire);
 
 public:
-    virtual ~Fire() override;
+    virtual ~Fire() override = default;
     void set_stat_label(RefPtr<GUI::Label> l) { stats = l; };
 
 private:
@@ -110,10 +111,6 @@ Fire::Fire()
     // update();
 }
 
-Fire::~Fire()
-{
-}
-
 void Fire::paint_event(GUI::PaintEvent& event)
 {
     GUI::Frame::paint_event(event);

Userland/Demos/LibGfxDemo/main.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2020, Linus Groh <linusg@serenityos.org>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -26,7 +27,7 @@ const int HEIGHT = 600;
 class Canvas final : public GUI::Widget {
     C_OBJECT(Canvas)
 public:
-    virtual ~Canvas() override;
+    virtual ~Canvas() override = default;
 
 private:
     Canvas();
@@ -42,10 +43,6 @@ Canvas::Canvas()
     draw();
 }
 
-Canvas::~Canvas()
-{
-}
-
 void Canvas::paint_event(GUI::PaintEvent& event)
 {
     GUI::Painter painter(*this);

Userland/Demos/LibGfxScaleDemo/main.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2020, Nico Weber <thakis@chromium.org>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -29,7 +30,7 @@ const int HEIGHT = 200;
 class Canvas final : public GUI::Widget {
     C_OBJECT(Canvas)
 public:
-    virtual ~Canvas() override;
+    virtual ~Canvas() override = default;
 
 private:
     Canvas();
@@ -62,10 +63,6 @@ Canvas::Canvas()
     update();
 }
 
-Canvas::~Canvas()
-{
-}
-
 void Canvas::paint_event(GUI::PaintEvent& event)
 {
     GUI::Painter painter(*this);

Userland/Demos/Screensaver/Screensaver.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, the SerenityOS developers.
+ * Copyright (c) 2020-2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -20,7 +20,7 @@
 class Screensaver final : public GUI::Widget {
     C_OBJECT(Screensaver)
 public:
-    virtual ~Screensaver() override;
+    virtual ~Screensaver() override = default;
 
 private:
     Screensaver(int width = 64, int height = 48, int interval = 10000);
@@ -44,10 +44,6 @@ Screensaver::Screensaver(int width, int height, int interval)
     draw();
 }
 
-Screensaver::~Screensaver()
-{
-}
-
 void Screensaver::mousemove_event(GUI::MouseEvent& event)
 {
     constexpr float max_distance_move = 10;

Userland/Demos/Starfield/Starfield.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2021, Jagger De Leo <jcdl@fastmail.com>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -32,7 +33,7 @@ struct Coordinate {
 class Starfield final : public GUI::Widget {
     C_OBJECT(Starfield)
 public:
-    virtual ~Starfield() override;
+    virtual ~Starfield() override = default;
     ErrorOr<void> create_stars(int, int, int);
 
     void set_speed(unsigned speed) { m_speed = speed; }
@@ -74,10 +75,6 @@ ErrorOr<void> Starfield::create_stars(int width, int height, int stars)
     return {};
 }
 
-Starfield::~Starfield()
-{
-}
-
 void Starfield::mousemove_event(GUI::MouseEvent&)
 {
 }

Userland/Demos/WidgetGallery/GalleryModels.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, the SerenityOS developers.
+ * Copyright (c) 2021-2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -17,7 +17,7 @@
 class MouseCursorModel final : public GUI::Model {
 public:
     static NonnullRefPtr<MouseCursorModel> create() { return adopt_ref(*new MouseCursorModel); }
-    virtual ~MouseCursorModel() override { }
+    virtual ~MouseCursorModel() override = default;
 
     enum Column {
         Bitmap,
@@ -86,7 +86,7 @@ public:
     }
 
 private:
-    MouseCursorModel() { }
+    MouseCursorModel() = default;
 
     struct Cursor {
         RefPtr<Gfx::Bitmap> bitmap;
@@ -101,7 +101,7 @@ private:
 class FileIconsModel final : public GUI::Model {
 public:
     static NonnullRefPtr<FileIconsModel> create() { return adopt_ref(*new FileIconsModel); }
-    virtual ~FileIconsModel() override { }
+    virtual ~FileIconsModel() override = default;
 
     enum Column {
         BigIcon,
@@ -189,7 +189,7 @@ public:
     }
 
 private:
-    FileIconsModel() { }
+    FileIconsModel() = default;
 
     struct IconSet {
         RefPtr<Gfx::Bitmap> big_icon;

Userland/Demos/WidgetGallery/GalleryWidget.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, the SerenityOS developers.
+ * Copyright (c) 2021-2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -328,7 +328,3 @@ GalleryWidget::GalleryWidget()
     m_icons_tableview->set_column_width(0, 36);
     m_icons_tableview->set_column_width(1, 20);
 }
-
-GalleryWidget::~GalleryWidget()
-{
-}

Userland/Demos/WidgetGallery/GalleryWidget.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, the SerenityOS developers.
+ * Copyright (c) 2021-2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -19,7 +19,7 @@
 class GalleryWidget final : public GUI::Widget {
     C_OBJECT(GalleryWidget)
 public:
-    virtual ~GalleryWidget() override;
+    virtual ~GalleryWidget() override = default;
 
 private:
     GalleryWidget();