Merge pull request #17 from kenluobo/add_virtual_method_test_case

Add virtual method test case

cplusplus/stl/11_virtual_method.cpp

@@ -0,0 +1,84 @@
+#include "utils/test.hpp"
+#include <cstdint>
+#include <string>
+
+//==================================================================
+enum class AnimalCategory : std::uint8_t {
+  LandAnimal = 0,
+  WaterAnimal,
+  Amphibian
+};
+
+static std::string convertAnimalCategoryToString(AnimalCategory AC) {
+  switch (AC) {
+  case AnimalCategory::LandAnimal:
+    return "LandAnimal";
+  case AnimalCategory::WaterAnimal:
+    return "WaterAnimal";
+  case AnimalCategory::Amphibian:
+    return "Amphibian";
+  }
+}
+
+//==================================================================
+class Animal {
+public:
+  virtual AnimalCategory getCategory() = 0;
+  virtual std::string getCategoryAsString() = 0;
+
+private:
+  AnimalCategory AC;
+};
+
+//==================================================================
+class Human : public Animal {
+public:
+  virtual AnimalCategory getCategory() { return AC; }
+  virtual std::string getCategoryAsString() {
+    return convertAnimalCategoryToString(AC);
+  }
+  virtual ~Human() = default;
+
+private:
+  AnimalCategory AC = AnimalCategory::LandAnimal;
+};
+
+class Employee : public Human {
+public:
+  virtual ~Employee() = default;
+};
+
+//==================================================================
+class Fish : public Animal {
+public:
+  virtual AnimalCategory getCategory() { return AC; }
+  virtual std::string getCategoryAsString() {
+    return convertAnimalCategoryToString(AC);
+  }
+
+private:
+  AnimalCategory AC = AnimalCategory::WaterAnimal;
+};
+
+//==================================================================
+void test_virtual_method() {
+  // todo
+  Human h;
+  out("Human ", h.getCategoryAsString());
+
+  Employee e;
+  out("Employee ", e.getCategoryAsString());
+
+  Fish f;
+  out("Fish ", f.getCategoryAsString());
+
+  Employee *p_e = &e;
+  out("Employee Pointer ", p_e->getCategoryAsString());
+  out("Human Pointer ", static_cast<Human *>(p_e)->getCategoryAsString());
+}
+
+//==================================================================
+void test() { TEST(test_virtual_method); }
+
+//==================================================================
+int main() { test(); }