cannot access private member declared in class

场景：'a' : cannot access private member declared in class 'father',该如何解决

'a' : cannot access private member declared in class 'father'

C/C++ code

#include<iostream>
using namespace std;

class father
{
public:
    father()
    {
        a = 0,b = 0;
    }
private:
    int a,b;

};


class Child
{

public:
    Child()
    {
        c = 1,d = 1;
    }
private:
    father gc;
    int c,d;
    friend void Print(Child & child);

};



void Print(Child & child)
{
    cout<<child.gc.a<<" "<<child.gc.b<<endl;
}





int main(void)
{
    Child test;
    Print(test);
    return 250;
}

我今天看书上的解题的时候，碰见了这个问题，错误提示如下
Compiling...
DosTest.cpp
d:\vc 6.0test\dostest\dostest.cpp(36) : error C2248: 'a' : cannot access private member declared in class 'father'
  d:\vc 6.0test\dostest\dostest.cpp(12) : see declaration of 'a'
d:\vc 6.0test\dostest\dostest.cpp(36) : error C2248: 'b' : cannot access private member declared in class 'father'
  d:\vc 6.0test\dostest\dostest.cpp(12) : see declaration of 'b'
Error executing cl.exe.

DosTest.exe - 2 error(s), 0 warning(s)
求高手解决

------解决方案--------------------

探讨

#include<iostream>
using namespace std;

class Child;

class father
{
friend void Print(Child &amp; child);

public:
father()
{
a = 0,b = 0;
}
private:
int a,b;

};


class Child
……