fix some warnings (#660)

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

examples/component/button.cpp

@@ -9,7 +9,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   int value = 50;
 
   // The tree of components. This defines how to navigate using the keyboard.

examples/component/button_animated.cpp

@@ -11,7 +11,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   int value = 50;
 
   // The tree of components. This defines how to navigate using the keyboard.

examples/component/button_in_frame.cpp

@@ -11,7 +11,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   int counter = 0;
   auto on_click = [&] { counter++; };
 

examples/component/button_style.cpp

@@ -10,7 +10,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   int value = 0;
   auto action = [&] { value++; };
   auto action_renderer =

examples/component/canvas_animated.cpp

@@ -14,7 +14,7 @@
 #include "ftxui/dom/canvas.hpp"                    // for Canvas
 #include "ftxui/screen/color.hpp"  // for Color, Color::Red, Color::Blue, Color::Green, ftxui
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
 
   int mouse_x = 0;

examples/component/checkbox.cpp

@@ -8,12 +8,12 @@
 #include "ftxui/component/screen_interactive.hpp"  // for Component, ScreenInteractive
 #include "ftxui/dom/elements.hpp"  // for operator|, Element, size, border, frame, vscroll_indicator, HEIGHT, LESS_THAN
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
 
   Component input_list = Container::Vertical({});
   std::vector<std::string> items(100, "");
-  for (int i = 0; i < items.size(); ++i) {
+  for (size_t i = 0; i < items.size(); ++i) {
     input_list->Add(Input(&(items[i]), "placeholder " + std::to_string(i)));
   }
 

examples/component/checkbox_in_frame.cpp

@@ -10,7 +10,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   std::array<bool, 30> states;
 
   auto container = Container::Vertical({});

examples/component/collapsible.cpp

@@ -26,7 +26,7 @@ Component Empty() {
   return std::make_shared<ComponentBase>();
 }
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto component =
       Collapsible("Collapsible 1",
                   Inner({

examples/component/composition.cpp

@@ -11,7 +11,7 @@ using namespace ftxui;
 
 // An example of how to compose multiple components into one and maintain their
 // interactiveness.
-int main(int argc, const char* argv[]) {
+int main() {
   auto left_count = 0;
   auto right_count = 0;
 

examples/component/custom_loop.cpp

@@ -11,7 +11,7 @@
 #include "ftxui/component/loop.hpp"       // for Loop
 #include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
   auto screen = ScreenInteractive::FitComponent();
 

examples/component/dropdown.cpp

@@ -5,7 +5,7 @@
 #include "ftxui/component/component.hpp"  // for Dropdown, Horizontal, Vertical
 #include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
 
   std::vector<std::string> entries = {

examples/component/flexbox_gallery.cpp

@@ -13,7 +13,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::Fullscreen();
 
   int direction_index = 0;

examples/component/focus.cpp

@@ -31,7 +31,7 @@ Element make_grid() {
   return gridbox(rows);
 };
 
-int main(int argc, const char* argv[]) {
+int main() {
   float focus_x = 0.5f;
   float focus_y = 0.5f;
 

examples/component/focus_cursor.cpp

@@ -19,7 +19,7 @@ Component Instance(std::string label, Decorator focusCursor) {
   });
 };
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::Fullscreen();
   screen.Loop(Container::Vertical({
       Instance("focus", focus),

examples/component/gallery.cpp

@@ -23,7 +23,7 @@ Component Wrap(std::string name, Component component) {
   });
 }
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::FitComponent();
 
   // -- Menu

examples/component/homescreen.cpp

@@ -24,7 +24,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::Fullscreen();
 
   // ---------------------------------------------------------------------------

examples/component/input.cpp

@@ -9,7 +9,7 @@
 #include "ftxui/dom/elements.hpp"  // for text, hbox, separator, Element, operator|, vbox, border
 #include "ftxui/util/ref.hpp"  // for Ref
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
 
   std::string first_name;

examples/component/input_style.cpp

@@ -10,7 +10,7 @@
 #include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
 #include "ftxui/dom/elements.hpp"  // for operator|=, Element, bgcolor, operator|, separatorEmpty, color, borderEmpty, separator, text, center, dim, hbox, vbox, border, borderDouble, borderRounded
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
 
   InputOption style_1 = InputOption::Default();

examples/component/linear_gradient_gallery.cpp

@@ -9,7 +9,7 @@
 #include "ftxui/component/component.hpp"       // for Slider, Renderer, Vertical
 #include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
   auto screen = ScreenInteractive::Fullscreen();
 

examples/component/maybe.cpp

@@ -10,7 +10,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   std::vector<std::string> entries = {
       "entry 1",
       "entry 2",

examples/component/menu.cpp

@@ -8,7 +8,7 @@
 #include "ftxui/component/component_options.hpp"   // for MenuOption
 #include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
   auto screen = ScreenInteractive::TerminalOutput();
 

examples/component/menu2.cpp

@@ -10,7 +10,7 @@
 #include "ftxui/component/screen_interactive.hpp"  // for Component, ScreenInteractive
 #include "ftxui/dom/elements.hpp"  // for text, separator, bold, hcenter, vbox, hbox, gauge, Element, operator|, border
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
   auto screen = ScreenInteractive::TerminalOutput();
 

examples/component/menu_entries.cpp

@@ -28,7 +28,7 @@ MenuEntryOption Colored(ftxui::Color c) {
   return option;
 }
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::TerminalOutput();
 
   int selected = 0;

examples/component/menu_entries_animated.cpp

@@ -24,7 +24,7 @@ MenuEntryOption Colored(ftxui::Color c) {
   return option;
 }
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::TerminalOutput();
 
   int selected = 0;

examples/component/menu_in_frame.cpp

@@ -10,7 +10,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   std::vector<std::string> entries;
   int selected = 0;
 

examples/component/menu_multiple.cpp

@@ -17,7 +17,7 @@ Component Window(std::string title, Component component) {
   });
 }
 
-int main(int argc, const char* argv[]) {
+int main() {
   int menu_selected[] = {0, 0, 0};
   std::vector<std::vector<std::string>> menu_entries = {
       {

examples/component/menu_style.cpp

@@ -30,7 +30,7 @@ Component HMenu3(std::vector<std::string>* entries, int* selected);
 Component HMenu4(std::vector<std::string>* entries, int* selected);
 Component HMenu5(std::vector<std::string>* entries, int* selected);
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::TerminalOutput();
 
   std::vector<std::string> entries{

examples/component/menu_underline_animated_gallery.cpp

@@ -27,7 +27,7 @@ Component Text(const std::string& t) {
   return Renderer([t] { return text(t) | borderEmpty; });
 }
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace std::literals;
   std::vector<std::string> tab_values{
       "Tab 1", "Tab 2", "Tab 3", "A very very long tab", "탭",

examples/component/modal_dialog_custom.cpp

@@ -8,7 +8,7 @@
 #include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
 #include "ftxui/dom/elements.hpp"  // for operator|, Element, filler, text, hbox, separator, center, vbox, bold, border, clear_under, dbox, size, GREATER_THAN, HEIGHT
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
   auto screen = ScreenInteractive::TerminalOutput();
 

examples/component/nested_screen.cpp

@@ -35,7 +35,7 @@ void Nested(std::string path) {
   screen.Loop(renderer);
 }
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::FitComponent();
   auto button_quit = Button("Quit", screen.ExitLoopClosure());
   auto button_nested = Button("Nested", [] { Nested(""); });

examples/component/print_key_press.cpp

@@ -134,7 +134,7 @@ std::string Stringify(Event event) {
   return out;
 }
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::TerminalOutput();
 
   std::vector<Event> keys;

examples/component/radiobox.cpp

@@ -7,7 +7,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   std::vector<std::string> radiobox_list = {
       "Use gcc",
       "Use clang",

examples/component/radiobox_in_frame.cpp

@@ -10,7 +10,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   std::vector<std::string> entries;
   int selected = 0;
 

examples/component/renderer.cpp

@@ -7,7 +7,7 @@
 #include "ftxui/dom/elements.hpp"  // for operator|, Element, text, bold, border, center, color
 #include "ftxui/screen/color.hpp"  // for Color, Color::Red
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
   auto screen = ScreenInteractive::FitComponent();
 

examples/component/resizable_split.cpp

@@ -8,7 +8,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::Fullscreen();
 
   auto middle = Renderer([] { return text("middle") | center; });

examples/component/slider.cpp

@@ -4,7 +4,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::TerminalOutput();
   int value = 50;
   auto slider = Slider("Value:", &value, 0, 100, 1);

examples/component/slider_direction.cpp

@@ -13,7 +13,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   auto screen = ScreenInteractive::TerminalOutput();
   std::array<int, 30> values;
   for (int i = 0; i < values.size(); ++i) {
@@ -21,10 +21,10 @@ int main(int argc, const char* argv[]) {
   }
 
   auto layout_horizontal = Container::Horizontal({});
-  for (int i = 0; i < values.size(); ++i) {
+  for (auto& value : values) {
     // In C++17:
     SliderOption<int> option;
-    option.value = &values[i];
+    option.value = &value;
     option.max = 100;
     option.increment = 5;
     option.direction = Direction::Up;

examples/component/slider_rgb.cpp

@@ -23,7 +23,7 @@ Element ColorString(int red, int green, int blue) {
   );
 }
 
-int main(int argc, const char* argv[]) {
+int main() {
   int red = 128;
   int green = 25;
   int blue = 100;

examples/component/tab_horizontal.cpp

@@ -10,7 +10,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   std::vector<std::string> tab_values{
       "tab_1",
       "tab_2",

examples/component/tab_vertical.cpp

@@ -10,7 +10,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   std::vector<std::string> tab_values{
       "tab_1",
       "tab_2",

examples/component/textarea.cpp

@@ -7,7 +7,7 @@
 #include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
 #include "ftxui/dom/elements.hpp"  // for operator|, separator, text, Element, flex, vbox, border
 
-int main(int argc, const char* argv[]) {
+int main() {
   using namespace ftxui;
 
   std::string content_1;

examples/component/toggle.cpp

@@ -10,7 +10,7 @@
 
 using namespace ftxui;
 
-int main(int argc, const char* argv[]) {
+int main() {
   std::vector<std::string> toggle_1_entries = {
       "On",
       "Off",