成员引用基类型"矩阵(向量 &，向量 &)不是结构或联合

当我尝试使用void print函数时，我收到错误"Member Reference base type'Matrix（Vector&，Vector&aamp；）不是结构或并集"。这个程序应该从用户那里获取值并将其存储在数据阵列中，然后它获取向量a和向量b并进行向量乘法以打印矩阵a。

    #include <iostream>
 using namespace std;
 const int rows=3;
 const int columns=3;
 const int elements=3;

 class Vector{
 private:
    double data[elements];
 public:
     Vector();
     void read();
     double get_element(int);
 };
 Vector::Vector(){
     int i=0;
     while(i<elements){data[i++]=0;}
 }
 Vector a;
 Vector b;
 Vector c;
 Vector d;
 void Vector::read(){
      int j=0;
      cout<<"Enter "<<elements<<" elements of vector a"<<endl;
     while(j<elements){cin>>data[j++];}

    }
    double Vector:: get_element(int n){
        while(n<elements)
            return data[n];
    }


    class Matrix {
            private:
                double data [rows*columns];
            public:
                Matrix(Vector &, Vector &);
                void add (const Matrix &);
                void mult (double);
                double trace();
                double norm();
                void print ();
    };
    Matrix::Matrix(Vector &, Vector &){
        int d,f;
                for (d=0; d<(rows); d++){
                    for (f=0; f<columns;f++){
                data[d*f]=a.get_element(d)*b.get_element(f);
    }
        }
    }
    Matrix A (Vector &a, Vector &b);
    Matrix B (Vector &c, Vector &d);
    void Matrix::print(){
        cout.precision(3);
                for (int i=0; i<rows; i++) {
                    cout << endl;
            for (int j=0; j<columns; j++) {
                cout << " " << data[i*j];
            }
        //This is printing Matrix A.
        }
    }
    int main(){
            a.read();
            b.read();
            c.read();
            d.read();
            A.print();
            //The error occurs here.
           return 0;
    }