C++类中定义 const static 成员变量为啥在VC++6.0中 编译不过

class GradeBook
{
public:
//constant -- number of students who took the test
const static int students = 0;

//constructor initialize course name and array of grades
GradeBook( string, const int [] );

void setCourseName( string );       //function to set the course name
string getCourseName();             //function to get the course name
void displayMessage();              //display a welcome message
void processGrades();               //perform various operations on the grade data
int getMinimum();                   //find the minimum grade for the test
int getMaximum();                   //find the maximum grade for the test
double getAverage();                //determine the average grade for the test
void outputBarChart();              //output bar chart of grade distribution
void outputGrades();                    //output the contents of the grades array

private:
string courseName; // course name for this grade book
int grades[ 10 ]; // array of student grades

};

显示students变量无法编译通过
错误代码 error C2252: 'students' : pure specifier can only be specified for functions
求大神解答，很多书上都这么写的

VC6.0不允许在类内初始化static const成员变量，你要在外面初始化：
const int GradeBook::students = 0;
这是VC6.0的bug吧，据说是VC6.0的协议太落后了，换个编译环境就不用这样了。