C++ reference_wrapper

reference_wrapper

• <functional> 라이브러리

• 템플릿 등에 레퍼런스로 전달할 수 있게 해주는 클래스이다.

---

예제

  #include <iostream>
  #include <vector>
  #include <functional>

  class Base
  {
  public:
    int    i_ = 0;

    virtual void print()
    {
      std::cout << "I'm Base\n";
    }
  };

  class Derived : public Base
  {
  public:
    int    j_ = 1;

    virtual void print() override
    {
      std::cout << "I'm Derived\n";
    }
  };

  void        doSomething(Base& b)
  {
    b.print();
  }

  int            main()
  {
    using namespace std;

    Base    b;
    Derived    d;

    vector<std::reference_wrapper<Base>> my_vec;
    my_vec.push_back(b);
    my_vec.push_back(d);

    for (auto& e : my_vec)
      e.get().print();
  }

  /* stdout
  I'm Base
  I'm Derived
  */