Bring back C++17 minimal requirement. (#475)

cmake/ftxui_set_options.cmake

@@ -9,7 +9,6 @@ endif()
 function(ftxui_set_options library)
   set_target_properties(${library} PROPERTIES
     VERSION ${PROJECT_VERSION}
-    CXX_STANDARD 20
     OUTPUT_NAME "ftxui-${library}"
   )
 

cmake/ftxui_test.cmake

@@ -71,6 +71,7 @@ target_include_directories(tests
   PRIVATE src
 )
 ftxui_set_options(tests)
+target_compile_features(tests PUBLIC cxx_std_20)
 
 include(GoogleTest)
 gtest_discover_tests(tests

codecov.yml

@@ -1,7 +1,7 @@
 codecov:
   require_ci_to_pass: no
   notify:
-    after_n_builds: 3
+    after_n_builds: 4
     wait_for_ci: yes
 
 coverage:

examples/component/slider_direction.cpp

@@ -1,7 +1,9 @@
 #include <array>                                  // for array
 #include <cmath>                                  // for sin
 #include <ftxui/component/component_base.hpp>     // for ComponentBase
-#include <ftxui/dom/elements.hpp>  // for size, GaugeDirection, GaugeDirection::Up, GREATER_THAN, HEIGHT
+#include <ftxui/component/component_options.hpp>  // for SliderOption
+#include <ftxui/dom/elements.hpp>  // for size, GREATER_THAN, GaugeDirection, GaugeDirection::Up, HEIGHT
+#include <ftxui/util/ref.hpp>  // for ConstRef, Ref
 #include <memory>              // for shared_ptr, __shared_ptr_access
 
 #include "ftxui/component/captured_mouse.hpp"  // for ftxui
@@ -19,12 +21,22 @@ int main(int argc, const char* argv[]) {
 
   auto layout_horizontal = Container::Horizontal({});
   for (int i = 0; i < values.size(); ++i) {
+    // In C++17:
+    SliderOption<int> option;
+    option.value = &values[i];
+    option.max = 100;
+    option.increment = 5;
+    option.direction = GaugeDirection::Up;
+    layout_horizontal->Add(Slider<int>(option));
+
+    /* In C++20:
     layout_horizontal->Add(Slider<int>({
         .value = &values[i],
         .max = 100,
         .increment = 5,
         .direction = GaugeDirection::Up,
     }));
+    */
   }
 
   layout_horizontal |= size(HEIGHT, GREATER_THAN, 20);

include/ftxui/screen/screen.hpp

@@ -2,7 +2,7 @@
 #define FTXUI_SCREEN_SCREEN_HPP
 
 #include <memory>
-#include <string>  // for allocator, string, basic_string
+#include <string>  // for string, allocator, basic_string
 #include <vector>  // for vector
 
 #include "ftxui/screen/box.hpp"       // for Box

src/ftxui/component/animation.cpp

@@ -1,5 +1,4 @@
 #include <cmath>    // IWYU pragma: keep
-#include <compare>  // for operator<=, operator>=, partial_ordering
 #include <ratio>    // for ratio
 #include <utility>  // for move
 

src/ftxui/component/radiobox.cpp

@@ -26,8 +26,7 @@ class RadioboxBase : public ComponentBase {
   RadioboxBase(ConstStringListRef entries,
                int* selected,
                Ref<RadioboxOption> option)
-      : entries_(entries), selected_(selected), option_(std::move(option)) {
-  }
+      : entries_(entries), selected_(selected), option_(std::move(option)) {}
 
  private:
   Element Render() override {

src/ftxui/component/screen_interactive.cpp

@@ -1,7 +1,6 @@
-#include <algorithm>  // for min
+#include <algorithm>  // for copy, max, min
 #include <array>      // for array
-#include <chrono>  // for operator-, milliseconds, duration, operator<=>, time_point, common_type<>::type
-#include <compare>  // for operator>=, strong_ordering
+#include <chrono>  // for operator-, milliseconds, duration, operator>=, time_point, common_type<>::type
 #include <csignal>  // for signal, raise, SIGTSTP, SIGABRT, SIGFPE, SIGILL, SIGINT, SIGSEGV, SIGTERM, SIGWINCH
 #include <cstdio>   // for fileno, size_t, stdin
 #include <ftxui/component/task.hpp>  // for Task, Closure, AnimationTask

src/ftxui/component/slider.cpp

@@ -266,12 +266,12 @@ Component Slider(ConstStringRef label,
                  ConstRef<int> min,
                  ConstRef<int> max,
                  ConstRef<int> increment) {
-  auto slider = Make<SliderBase<int>>(SliderOption<int>({
-      .value = value,
-      .min = min,
-      .max = max,
-      .increment = increment,
-  }));
+  SliderOption<int> option;
+  option.value = value;
+  option.min = min;
+  option.max = max;
+  option.increment = increment;
+  auto slider = Make<SliderBase<int>>(option);
   return Make<SliderWithLabel>(label, slider);
 }
 
@@ -280,12 +280,12 @@ Component Slider(ConstStringRef label,
                  ConstRef<float> min,
                  ConstRef<float> max,
                  ConstRef<float> increment) {
-  auto slider = Make<SliderBase<float>>(SliderOption<float>({
-      .value = value,
-      .min = min,
-      .max = max,
-      .increment = increment,
-  }));
+  SliderOption<float> option;
+  option.value = value;
+  option.min = min;
+  option.max = max;
+  option.increment = increment;
+  auto slider = Make<SliderBase<float>>(option);
   return Make<SliderWithLabel>(label, slider);
 }
 Component Slider(ConstStringRef label,
@@ -293,12 +293,12 @@ Component Slider(ConstStringRef label,
                  ConstRef<long> min,
                  ConstRef<long> max,
                  ConstRef<long> increment) {
-  auto slider = Make<SliderBase<long>>(SliderOption<long>({
-      .value = value,
-      .min = min,
-      .max = max,
-      .increment = increment,
-  }));
+  SliderOption<long> option;
+  option.value = value;
+  option.min = min;
+  option.max = max;
+  option.increment = increment;
+  auto slider = Make<SliderBase<long>>(option);
   return Make<SliderWithLabel>(label, slider);
 }