c++ - error LNK2019: unresolved external symbol "public: __thiscall

itemprop="text">

I have a class like

template             T>
 class LinkedListItem

 {

            public:
 LinkedListItem(T value);
 LinkedListItem(const
            LinkedListItem& rhs);
 T getValue(void);

            LinkedListItem& getNext(void);
 void
            setNext(LinkedListItem& next);
 LinkedListItem&
            operator=(const LinkedListItem& rhs);

            ~LinkedListItem();
 private:

 T _value;

            LinkedListItem& _next;

            };

I am trying to
write a unit test
like

TEST_CLASS(LinkedListUnitTests)
{
public:



            TEST_METHOD(Add_to_An_Empty_Linked_List)
 {

            LinkedListItem item(1);

            }
//private:

};

When
I try to just build the above code I get the ugly error
-

error LNK2019: unresolved external symbol
"public: __thiscall cpp::libraries::datastructures::LinkedListItem::LinkedListItem(int)"
(??0?$LinkedListItem@H@datastructures@libraries@cpp@@QAE@H@Z) referenced in function
"public: void __thiscall
CppLibrariesTests::LinkedListUnitTests::Add_to_An_Empty_Linked_List(void)"
(?Add_to_An_Empty_Linked_List@LinkedListUnitTests@CppLibrariesTests@@QAEXXZ)

I
am using Visual Studio 2012.

Interestingly, If I
add template in the unit test class like below the compile error goes away but the tests
are not discovered and I can't run
them.

template            T>
TEST_CLASS(LinkedListUnitTests){..}

I
am trying to pick up C++ after a long time so I won't be surprised if I am doing
something very stupid. Any thoughts anyone?

class="post-text" itemprop="text">

class="normal">Answer

Templates
must ideally be implemented inline. Second pass of compiler cannot re use the CPP file
that has the implementation. Or, you need to #include the
CPP file also.

href="http://www.codeproject.com/Articles/257589/An-Idiots-Guide-to-Cplusplus-Templates-Part"
rel="nofollow">Refer this article