C++ Nested Types

Nested Types

• 클래스 안에서만 사용하는 자료형은 클래스 내부에 정의하는게 좋다.

---

예제

• unscoped enum 사용

  #include <iostream>
  
  class Fruit
  {
  public:
    enum FruitType
    {
      APPLE, BANANA, CHERRY
    };
  
  private:
    FruitType    type_;
  
  public:
    Fruit(FruitType type) : type_(type)
    {}
  
    FruitType    getType()
    {
      return type_;
    }
  };
  
  int        main()
  {
    Fruit    apple(Fruit::APPLE);
  
    if (apple.getType() == Fruit::APPLE)
    {
      std::cout << "Apple" << std::endl;
    }
  }
  
  /* stdout
  Apple
  */

• enum class 사용

  #include <iostream>
  
  class Fruit
  {
  public:
    enum class FruitType
    {
      APPLE, BANANA, CHERRY
    };
  
  private:
    FruitType    type_;
  
  public:
    Fruit(FruitType type) : type_(type)
    {}
  
    FruitType    getType()
    {
      return type_;
    }
  };
  
  int        main()
  {
    Fruit    apple(Fruit::FruitType::APPLE);
  
    if (apple.getType() == Fruit::FruitType::APPLE)
    {
      std::cout << "Apple" << std::endl;
    }
  }
  
  /* stdout
  Apple
  */