What lines have errors when compiling this code?

#include <iostream>

using namespace std;

class Test
{
public:
    bool flag;
    Test () { flag = false; }
    static int ObjectCount; // 1
    static void POut () // 2
    {
        cout << flag; // 3
        cout << ObjectCount; // 4
    }
};

int Test::ObjectCount = 0; // 5

int main ()
{
    Test T;
}

Explanation

In static function members, it's not possible to access non-static class data members directly. Everything is tied to this pointer. If non-static member functions of a class receive this pointer implicitly, then static member functions of the class do not receive it, since static data members are used by all instances of this class.