请教各位大神 undefined reference to 问题

#ifndef VECTOR_H

#define VECTOR_H

#define DEFAULT_CAPACITY 3



typedef int Rank;



template <typename T>class Vector

{

    private:

    Rank _size;

    int _capacity;

    T* _elem;

    public:

//      void expand();

//      void shrink();

//

      void copyForm(T* const A,Rank lo,Rank hi);

//

//      bool bubble(Rank lo,Rank hi);

//      void bubbleSort(Rank lo,Rank hi);

//      void Vector<T> exchange(Rank i,Rank j);

//      Rank selectMax(Rank lo,Rank hi);

//      void merge(Rank lo,Rank hi);

//      void mergeSort(Rank lo,Rank hi);

//      Rank partition(Rank lo,Rank hi);

//      void quickSort(Rank lo,Rank hi);

//      void heapSort(Rank lo,Rank hi);



      Vector(int c = DEFAULT_CAPACITY){_elem = new T[_capacity = c];_size = 0;}

      Vector(T* A,Rank lo,Rank hi){copyForm(A,lo,hi);}//区间复制//

      Vector(T* A,Rank n){copyForm(A,0,n);}//从头复制//

      Vector(Vector<T> const& v,Rank lo,Rank hi){copyForm(v._elem,lo,hi);}//

      Vector(Vector<T> const& v){copyForm(v._elem,0,v._size);}//



      ~Vector(){delete[] _elem;}//

//只读访问接口 相当于属性

//      Rank size() const//

//      {

//          return _size;

//      }

//      bool empty() const {return _size<=0;}//

//      int disordered() const;//

//      Rank find(T const& e)const {return find(e,0,(Rank)_size);}//

//      Rank find(T const& e,Rank lo,Rank hi)const;//

//      Rank search(T const &e)const//

//      {

//          return (0>=_size)?-1:search(e,(Rank)0,(Rank)_size);

//      }

//      Rank search(T const& e,Rank lo,Rank hi)const;//

//

//      //可写接口

      T& operator[](Rank r)const;

//      Vector<T>& operator=(Vector<T> const&)const;//

//      T remove(Rank r);//

//      int remove(Rank lo,Rank hi);//

//      Rank insert(Rank r,T const&e);//

//      Rank insert(T const&e){return insert(_size,e);}//

//      void sort(Rank lo,Rank hi);//

//      void sort(){sort(0,_size);}//

//      void unsort(Rank lo,Rank hi);//

//      void unsort(){unsort(0,_size);}//

//      int deduplicate();//

//      int uniquify();//

//      //遍历

//      void traverse(void(*)(T&)); //使用函数指针 只读或局部修改//

//      template<typename VST> void traverse(VST&);//使用函数对象 可全局性修改//









};









#endif

#include "Vector1.h"

template <typename T> void  Vector<T>::copyForm(T* const A,Rank lo,Rank hi)

{

    _elem = new T[_capacity = 2*(hi-lo)];

    _size = 0;

    while(lo<hi)

        _elem[_size++] = A[lo++];



}



template <typename T> T& Vector<T>::operator[](Rank i)const

{

    return _elem[i];

}

#include <iostream>

#include "Vector1.h"

using namespace std;



int main()

{

    int arr[4] = {1,2,3,4};

    Vector<int> v1(arr,4);

    return 0;

}