C++ nullptr_t

nullptr_t

• C++11

• C언어에서 사용되지는 않으나, <cstddef> 라이브러리에 존재하는 자료형이다.

  #include <cstddef>
  #include <iostream>
  
  void f(int*)
  {
      std::cout << "Pointer to integer overload\n";
  }
  
  void f(double*)
  {
      std::cout << "Pointer to double overload\n";
  }
  
  void f(std::nullptr_t)
  {
      std::cout << "null pointer overload\n";
  }
  
  int main()
  {
      int* pi {}; double* pd {};
  
      f(pi);
      f(pd);
      f(nullptr); // would be ambiguous without void f(nullptr_t)
      // f(0);    // ambiguous call: all three functions are candidates
      // f(NULL); // ambiguous if NULL is an integral null pointer constant 
                  // (as is the case in most implementations)
  }

--- 참고

• cppreference