I want to create object of inner class in C++, or may be nested class

Suppose I have outer class as A and a inner class B

template <class T, class K>
class A::public T::RadioSignal, public VarMethod<T> {
private:
B *bObject;
public:
class B : public std::vector<SamplePoint*>
    {
    public:
        B(A<K, T> *outerInstance);
    };
}

I am getting below error: Unknown type name 'B'