关于两个类是否可以相互设置为友员?
代码如下:
//把A、B两个类相互设置为友员类,为什么编译有错
class B;
class A
{
friend class B;
private:
int A_data;
public:
void A_f()
{
B b;
b.B_data=1000;
}
};
class B
{
friend class A;
private:
int B_data;
public:
void B_f()
{
A a;
a.A_data=1000;
}
};
/*
编译环境:MS VC6.0
--------------------Configuration: aa - Win32 Debug--------------------
Compiling...
aa.cpp
F:\ASD\aa\aa.cpp(12) : error C2079: 'b' uses undefined class 'B'
F:\ASD\aa\aa.cpp(13) : error C2228: left of '.B_data' must have class/struct/union type
Error executing cl.exe.
aa.obj - 2 error(s), 0 warning(s)
*/