奇怪的小错误

这是我对错误的处理：

In file included from braincalc.cpp:8:0:
AbstractStack.h:43:1: error: expected class-name before â{â token

这是我的.h：

/AbstractStack.h

#ifndef ABSTRACTSTACK_H
#define ABSTRACTSTACK_H
#include<iostream>
using namespace std;
template < typename T >
class AbstractStack
{
public:
  // Purpose: clears the stack
  // Postconditions: the stack is now empty 
  virtual void clear() = 0;
  // Purpose: push an element into the stack
  // Parameters: x is the value to push into the stack
  // Postconditions: x is now the element at the top of the stack, 
  virtual void push(T x) = 0;

  // Purpose: pop the stack
  // Postconditions: the element formerly at the top of the stack has
  // been removed
  // Panic: if the stack is currently empty, PANIC!
  virtual void pop() = 0;

  // Purpose: looks at the top of the stack
  // Returns: a reference to the element currently on top of the stack
  // Panic: if the stack is currently empty, PANIC!
  virtual T& top() = 0;

  // Purpose: Checks if a stack is empty
  // Returns: 'true' if the stack is empty
  //     'false' otherwise  
  virtual bool isEmpty() = 0;
};
class LinkedStack: public AbstractStack
{
  public:
    int m_data;
    LinkedStack *m_next;
    void clear()
    {
      LinkedStack *p;
      LinkedStack *tmp;
      while(m_next != NULL)
      {
        p = this;
        tmp = p -> m_next;
        delete p;
      }
    } 
    void push(int x)
    {
      LinkedStack *tmp = new LinkedStack;
      tmp -> m_data = m_data;
      tmp -> m_next = m_next;
      m_data = x;
      m_next = tmp;
    }
    void pop()
    {
      LinkedStack *tmp;
      if (m_next != NULL)
      {
        tmp = m_next;
        m_data = tmp -> m_data;
        m_next = tmp -> m_next;
        delete tmp;
      }
    }
    int& top()
    {
        return m_data;
    }
    bool isEmpty()
    {
      bool empty = false;
      if (m_next == NULL)
      {
        empty = true;
      }
      return empty;
    }
};
#endif

以下是.cpp：

脑计算.cpp

#include"AbstractStack.h"
#include<string>
#include<cstdlib>

int main()
{
  string input;
  bool again=true;
  int ctr=0;
  int temp1, temp2;
  LinkedStack stack;
  do
  {
    getline(cin, input, '$');
    input.c_str();
    if (isdigit(input[ctr]))
    {
      stack.push(atoi(&input[ctr]));
      ctr++;
    }
    else if (isspace(input[ctr]))
    {
      ctr++;
    }
    else if (input[ctr] == '*')
    {
      temp2 = stack.top();
      stack.pop();
      temp1 = stack.top();
      stack.pop();
      stack.push(temp1 * temp2);
      ctr++;
    }
    else if (input[ctr] == '/')
    {
      temp2 = stack.top();
      stack.pop();
      temp1 = stack.top();
      stack.pop();
      stack.push(temp1 / temp2);
      ctr++;
    }
    else if (input[ctr] == '+')
    {
      temp2 = stack.top();
      stack.pop();
      temp1 = stack.top();
      stack.pop();
      stack.push(temp1 + temp2);
      ctr++;
    }
    else if (input[ctr] == '-')
    {
      temp2 = stack.top();
      stack.pop();
      temp1 = stack.top();
      stack.pop();
      stack.push(temp1 - temp2);
      ctr++;
    }
    else if (input[ctr] == '!')
    {
      temp1 = stack.top();
      stack.pop();
      stack.push(-temp1);
      ctr++;
    }
    else if (input[ctr] == '#')
    {
      again = false;
      ctr=0;
    }
  } while(again == true);
  cout << "["<<stack.top()<<"]"<<endl;
  return 0;
}

意识到代码没有完成，但是这个错误使我无法测试它是否像我认为的那样工作。 提前谢谢。