Vector circular dependency without headers : error C2061

So I am creating a project that involves having vectors nested inside one another, but the structure won't compile. I think this is a case of circular dependency, but all of the fixes I've seen seem to only apply to code involving header files.

#include<iostream>
#include<vector>

using namespace std;

class A
{
    virtual ~A();
};

class B : public A
{
    vector<A*> Avector;

    void addC(C* Cin){Avector.push_back(Cin);};
    ~B();
};

class C : public A
{
    vector<A*> Avector;

        void addB(B* Bin){Avector.push_back(Bin);};
        ~C();
    };

int main()
{

}

I've tried forward declaring with

class C;

Class C : public A;

But none of it seems to work.

The error I get is:

\test\test\source.cpp(15): error C2061: syntax error : identifier 'C'
\test\test\source.cpp(15): error C2065: 'Cin' : undeclared identifier

Is this sort of code implementable?

Thanks for taking the time to read this.