Creating a linked list, templated Stack

Question

I am trying to compile the code my instructor has given us (had to retype it, but I can't find any typos) and it will not compile. We will be using this code for later assignments so I want to make it work before we get there.

It should simply make a linked-list based stack. I understand how the code works, and I have done templates before, but I can't figure out why it won't compile.

First Stack.h

#ifndef STACK_H
#define STACK_H
//Stack definition file
//Stack.h



template<class ItemType>
struct NodeType<ItemType>; //Line 9



template<class ItemType>
class StackType {
public:
    StackType();
    ~StackType();
    void MakeEmpty();
    void Push(ItemType);
    void Pop(ItemType &);
    bool IsEmpty() const;
    bool IsFull() const;
    ItemType Top();

private:
    NodeType* topPtr;
};


template<class ItemType>
struct NodeType<ItemType> {
    int info;
    NodeType<ItemType>* next;
}; //Line 34

#include "Stack.cpp"

#endif

Stack.cpp

//Stack implemenation
#include <iostream>

template<class ItemType>
StackType<ItemType>::StackType() { //Line 5
    topPtr=NULL;
}


template <class ItemType>
StackType<ItemType>::~StackType() { //Line 11
    MakeEmpty();
}



template <class ItemType>
void StackType<ItemType>::MakeEmpty() {
    NodeType<ItemType>* tempPtr;

    while (topPtr != NULL) {
        tempPtr = topPtr;
        topPtr = topPtr->next;
        delete tempPtr;
    }
}

template <class ItemType>
void StackType<ItemType>::Pop(ItemType & item) {

    NodeType<ItemType>* tempPtr;
    item = topPtr->info;
    tempPtr = topPtr;
    topPtr = topPtr->next;
    delete tempPtr;
}

template<class ItemType>
void StackType<ItemType>::Push(ItemType item) {
    NodeType<ItemType>* location;
    location = new NodeType<ItemType>;
    location->info = newItem;
    location->next = topPtr;
    topPtr = location;
}

template <class ItemType>
bool StackType<ItemType>::IsEmpty() const {
    return (topPtr=NULL);
}

template <class ItemType>
bool StackType<ItemType>::IsFull() const {
    return (false);
}

template<class ItemType>
ItemType StackType<ItemType>::Top() {
        return topPtr->info;
}

and main.cpp

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

int main () {

    int whatever;
    StackType<int> s;
    s.Push(10);
    s.Push(1);
    s.Pop(whatever);
    return 0;

}

The errors I get are

c:\users\geldhart\dropbox\cs210\stack\stack.h(9):
error C2143: syntax error : missing ';' before '<'
c:\users\geldhart\dropbox\cs210\stack\stack.h(9):
error C2059: syntax error : '<'
c:\users\geldhart\dropbox\cs210\stack\stack.h(34):
error C2753: 'NodeType' : partial specialization cannot match argument list for primary template
Stack.cpp
c:\users\geldhart\dropbox\cs210\stack\stack.cpp(5):
error C2143: syntax error : missing ';' before '<'
c:\users\geldhart\dropbox\cs210\stack\stack.cpp(5):
error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
c:\users\geldhart\dropbox\cs210\stack\stack.cpp(5):
error C2988: unrecognizable template declaration/definition
c:\users\geldhart\dropbox\cs210\stack\stack.cpp(5):
error C2059: syntax error : '<'
c:\users\geldhart\dropbox\cs210\stack\stack.cpp(11):
error C2588: '::~StackType' : illegal global destructor
c:\users\geldhart\dropbox\cs210\stack\stack.cpp(11):
fatal error C1903: unable to recover from previous error(s); stopping compilation

Answer 1

This syntax

template<class ItemType>
struct NodeType<ItemType>; //Line 9

would possibly be for partially specializing some existing NodeType.

To (forward) declare the type, you just need

template<class ItemType>
struct NodeType;