cpp class variable

cpp에서는 class variable을 쓸 때,
어떤 cpp 파일에

12	int Something::s_nIDGenerator = 1;

를 한 번 더 정의해줘야 하네.

01	class Something

02

{

03

private:

04	static int s_nIDGenerator;

05	int m_nID;

06

public:

07	Something() { m_nID = s_nIDGenerator++; }

08

09	int GetID() const { return m_nID; }

10

};

11

12	int Something::s_nIDGenerator = 1;

13

14	int main()

15

{

16	Something cFirst;

17	Something cSecond;

18	Something cThird;

19

20	using namespace std;

21	cout << cFirst.GetID() << endl;

22	cout << cSecond.GetID() << endl;

23	cout << cThird.GetID() << endl;

24

return 0;

25

}

http://www.learncpp.com/cpp-tutorial/811-static-member-variables/