Error: LNK2019 Error

[darkeclipse8]

---------------------------------------------TSet.h------------------------------------------------------

#include <iostream>
using namespace std;

template <class V>
class TSet
{
    public:
        TSet();
        TSet(int size);
        ~TSet();
        void add(V new_item);
        void remove(V item_to_remove);
        int num_of_items();
        bool isFull();
        bool is_item_in_set(V item);
        friend bool operator==(const TSet<V>& left, const TSet<V>& right);
        friend bool operator!=(const TSet<V>& left, const TSet<V>& right);
        friend ostream& operator<<(ostream& outs,const TSet<V>& list);

    private:
        V *item_list;
        int size_of_list;
        int current_size;
};

----------------------------------------TSet.cpp-----------------------------------------

#include <iostream>
#include "TSet.h"
using namespace std;

template<class V>
TSet<V>::TSet() : size_of_list(0), current_size(0)
{   item_list = new V[0];   }

template<class V>
TSet<V>::TSet(int size) : size_of_list(size), current_size(0)
{   item_list = new V[size];    }

template<class V>
TSet<V>::~TSet()
{   delete [] item_list;    }

template<class V>
void TSet<V>::add(V new_item)
{
    if(isFull())
        cout << "Unable to add element " << new_item << " to set that is full.\n";
    else
    {
        item_list[current_size] = new_item;
        current_size = current_size + 1;
        cout << new_item << " was added to the set." << endl;
    }
}

template<class V>
void TSet<V>::remove(V item_to_remove)
{
    for(int i = 0; i < current_size; i++)
    {
        if(item_list[i] == item_to_remove)
        {
            item_list[i] = NULL;
            cout << "Successfully removed " << item_to_remove << " from the set.\n";
            for(int j = i; i <= current_size; i++)
            {
                item_list[i] = item_list[i+1];
                currentSize = currentSize - 1;
            }
        }
    }
}

template<class V>
int TSet<V>::num_of_items()
{
    int element_count;
    for(int i = 0; i < size_of_list)
    {
        if(item_list[i] != NULL)
        {   element_count++;    }
    }

    return element_count;
}

template<class V>
bool TSet<V>::isFull()
{
    if(current_size == size_of_list)
        return true;

    return false;
}

template<class V>
bool TSet<V>::is_item_in_set(V item)
{
    for(int i = 0; i < current_size; i++)
    {
        if(item_list[i] == item)
        {   return true;    }
    }

    return false;
}

template<class V>
bool operator==(const TSet<V>& left, const TSet<V>& right)
{
    return left == right;
}

template<class V>
bool operator!=(const TSet<V>& left, const TSet<V>& right)
{
    return !(left == right);
}

template<class V>
ostream& operator<<(ostream& outs,const TSet<V>& list)
{
    for(int i = 0; i < list.current_size; i++)
    {   outs << list.item_list[i] << " ";   }

    return outs;
}

------------------------------------TSet_Driver.cpp-------------------------------------------------------

#include <iostream>
#include "TSet.cpp"
using namespace std;

int main()
{
    TSet<int> int_list(5);
    for(int i = 1; i <= 5; i++)
    {   int_list.add(i);    }
    cout << "int_list: " << int_list << endl;
    int_list.add(6);
    system("Pause");
    return 0;
}

-----------------------------------------------------------------------------------------------------------

When I compile this Microsoft Visual C++ 2010 Express. I get this:

1>------ Build started: Project: TSet, Configuration: Debug Win32 ------
1> TSet_Driver.cpp
1> LINK : C:\Users\name\Documents\Dropbox\TSet\Debug\TSet.exe not found or not built by the last incremental link; performing full link
1>TSet_Driver.obj : error LNK2019: unresolved external symbol "class std::basic_ostream<char,struct std::char_traits<char> > & __cdecl operator<<(class std::basic_ostream<char,struct std::char_traits<char> > &,class TSet<int> const &)" (??6@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@std@@AAV01@ABV?$TSet@H@@@Z) referenced in function _main
1>C:\Users\name\Documents\Dropbox\TSet\Debug\TSet.exe : fatal error LNK1120: 1 unresolved externals
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

What did I mess up here? Any answers?