Cannot access private member declared in class

Question

I have to write a C++ code must also perform sorting of multiple objects of the following class:

class student
{
    int roll, m[5], total;
    bool pass;
    char name[30];
public:
    void read();
    void result();
    void print();
    void operator=(student&);
    friend void sort(student, int);
};
void sort(student var[], int size)
{
    int s,t;
    for (s = 0; s<size; s++)
    for (t = 0; t<size; t++)
    {
        if (var[s].total<var[t].total)      //---------line 22----------
    {   
            student x;
            x = var[s];
            var[s] = var[t];
            var[t] = x;
        }
    }
}

void student::operator=(student &x)
{
roll=x.roll;
strcpy_s(name,x.name);
for(int v=0;v<5;v++)
m[v]=x.m[v];
total=x.total;
pass=x.pass;
}
void main()
{
student s[4];
int ni, n;
cout<<"Enter number of student records: ";
cin >> n;
for (ni = 0; ni<n; ni++)
{
    s[ni].read();
    s[ni].result();

}
sort(s, n);
cout<<endl<<"List sorted based on total: "<<endl;
for (ni = 0; ni<n; ni++)
{
    s[ni].print();
}
}

I use Visual C++ 2008. When I compiled this code it displays two errors:

Error1 error C2248:'student::total': cannot access private member declared in class 'student'


Error2 error C2248:'student::total': cannot access private member declared in class 'student'

These errors are shown at same line 22 that is while accessing total. Although sort() is a friend function I get this accessibility error.

I noted that if total declared public, there is no error. but as per class specification it has to be private. Please help me.

Answer 1

The correct friend function declaration will look like

friend void sort(student[], int);

There is a difference between the function declaration and the function definition in your code. They do not coincide Take into account that the correct declaration of the copy assignment operator will look like

student & operator =( const student & );     

Also function main shall have return type int

int main()