C++类的编译错误，请教~~~

C/C++ code

#include<stdio.h>class B;class A{public:    void ap(B * cl)    {        cl->print();        printf("calss A\n");    }};class B{public:    void print()    {        printf("class B\n");    }    void bp()    {        A a;        a.ap(this);    }};void main(){}

C:\Documents and Settings\Administrator\test.cpp(10) : error C2027: use of undefined type 'B'
C:\Documents and Settings\Administrator\test.cpp(3) : see declaration of 'B'
C:\Documents and Settings\Administrator\test.cpp(10) : error C2227: left of '->print' must point to class/struct/union

[解决办法]
试试？

C/C++ code

#include<stdio.h>class B;class A{public:    void ap(B * cl);};class B{public:    void print()    {        printf("class B\n");    }    void bp();};void A::ap(B * cl);    {        cl->print();        printf("calss A\n");    }    void B::bp()    {        A a;        a.ap(this);    }void main(){}
[解决办法]
楼上，这种方法有解决办法没？A中有B，B中有A的