Template Specialization with External Errors - c++

Question

When I attempted to specialize one of my template functions, Visual Studio threw me an external error, including an error for a function that was not specialized.
The three errors:
1>------ Build started: Project: Project3, Configuration: Debug Win32 ------
1>main.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall linearList<class FriendToken>::reverse(void)" (?reverse#?$linearList#VFriendToken####UAEXXZ)
1>main.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall linearList<class FriendToken>::print(void)" (?print#?$linearList#VFriendToken####UAEXXZ)
1>main.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall linearList<class FriendToken>::insertionSort(void)" (?insertionSort#?$linearList#VFriendToken####UAEXXZ)
Here is the relevant part of the code:
template<class T>
class arrayList : public linearList<T>
{
public:
//other methods
void reverse();
void print();
void insertionSort();
};
template<class T>
void arrayList<T>::reverse()
{
//method body
}
template<>
void arrayList<FriendToken>::insertionSort()
{
//method body
}
template<>
void arrayList<FriendToken>::print()
{
//method body
}
template<class T>
void arrayList<T>::insertionSort(){}
template<class T>
void arrayList<T>::print(){}

Answer 1

Your example shows specializations of the arrayList member functions which I assume are supposed to be overriding their virtual equivalants in linearList. The linker is saying it cant find the virtual members in the class linearList which is not included in your example.
virtual void __thiscall linearList<class FriendToken>::reverse(void)
If I add a definition of linearList like this the linker is quiet (on MSVC2010, I also added a empty FriendToken class to make things work).
template<typename T>
class linearList
{
public:
virtual void reverse() = 0; //pure virtual
virtual void print() = 0;
virtual void insertionSort() = 0;
};
If this is not your problem please post the code for linearList and I will update my answer as that is surely the source of your problem.
If needed for reference here is how I used the function reverse to test:
arrayList<FriendToken> a;
static_cast<linearList<FriendToken>&>(a).reverse();