Update example on multiple inheritance

Author: XuhuaHuang

MultipleInheritance/CMakeLists.txt

@@ -2,8 +2,11 @@ cmake_minimum_required(VERSION 3.20)
 
 project("multiple_inheritance" LANGUAGES CXX)
 
-set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
 add_executable(date_time "date_time.cpp")
 add_executable(coloured_circle "coloured_circle.cpp")
+add_executable(modern_coloured_circle "modern_coloured_circle.cpp")

MultipleInheritance/modern_coloured_circle.cpp

@@ -0,0 +1,82 @@
+#include <iostream>
+#include <string>
+#include <string_view>
+
+namespace constants {
+constexpr double pi = 3.14159265358979323846;
+}
+
+class circle_t {
+private:
+  int radius{0};
+
+public:
+  circle_t() = default;
+
+  explicit circle_t(int r)
+    : radius(r) {}
+
+  void set_radius(int r) { radius = r; }
+
+  [[nodiscard]]
+  int get_radius() const noexcept {
+    return radius;
+  }
+
+  [[nodiscard]]
+  double get_area() const noexcept {
+    return static_cast<double>(radius) * radius * constants::pi;
+  }
+};
+
+class colour_t {
+private:
+  std::string line_colour{"none"};
+  std::string fill_colour{"none"};
+
+public:
+  colour_t() = default;
+
+  explicit colour_t(std::string_view colour)
+    : line_colour(colour)
+    , fill_colour(colour) {}
+
+  void set_line_colour(std::string_view colour) { line_colour = colour; }
+
+  void set_fill_colour(std::string_view colour) { fill_colour = colour; }
+
+  [[nodiscard]]
+  const std::string& get_line_colour() const noexcept {
+    return line_colour;
+  }
+
+  [[nodiscard]]
+  const std::string& get_fill_colour() const noexcept {
+    return fill_colour;
+  }
+};
+
+class coloured_circle_t : public circle_t, public colour_t {
+public:
+  coloured_circle_t() = default;
+
+  coloured_circle_t(int radius, std::string_view colour)
+    : circle_t(radius)
+    , colour_t(colour) {}
+};
+
+int main() {
+  coloured_circle_t ccobj1;
+  std::cout << "\nDefault constructor:\n"
+            << "Area: " << ccobj1.get_area() << "\n"
+            << "Line colour: " << ccobj1.get_line_colour() << "\n"
+            << "Fill colour: " << ccobj1.get_fill_colour() << "\n";
+
+  coloured_circle_t ccobj2(2, "red");
+  std::cout << "\nOverloaded constructor:\n"
+            << "Area: " << ccobj2.get_area() << "\n"
+            << "Line colour: " << ccobj2.get_line_colour() << "\n"
+            << "Fill colour: " << ccobj2.get_fill_colour() << "\n";
+
+  return 0;
+}