系统:Linux 编译器:GCC 4.4.6版问题与函数指针在出队函数用于链表队列
计划是在教师指定的要使用的功能的大专水平班提供课程。我只能对这两个文件进行更改,而不能对教师提供的任何文件进行更改。该程序似乎运行正常,除了我的实现出列函数。我需要访问前面,后面,项目和计数。编译器说他们超出了范围。我能够从cpp文件中的其他功能访问它们,但由于不同的方法,这个使用我很难过。从我发现这是一个函数指针。我从来没有与这些工作过,唯一的文档,我可以找到他们是如何使用它们,但没有关于如何从函数外部访问成员没有发送英寸任何帮助,将不胜感激。我一直在为此工作数日,无法决定如何解决问题。
////////////////////////////////////////////////////////////////////////////////////////////
//My.h
#ifndef __LINKEDQUEUE_H__
#define __LINKEDQUEUE_H__
#include <ostream>
#include <stdint.h>
#include "task.h"
#include "queueExceptions.h"
#include <string>
#include <new>
#include "queue.h"
/*class QueueEmpty
{};
class QueueFull
{};
*/
typedef Task* ItemType;
struct NodeType {
ItemType info;
NodeType* next;
};
class LinkedQueue: public Queue
{
public:
int count;
NodeType* front;
NodeType* rear;
LinkedQueue();
~LinkedQueue();
/**
* Enqueue a task onto the queue
* @param tsk The task to enqueue
* @throws QueueFull if there is not room on the queue to place the item.
*/
void enqueue(Task *tsk) throw (QueueFull);
/**
* Dequeue an element from the queue.
* @return the front of the queue.
* @throws QueueEmpty if there are no elements in the queue.
*/
Task *dequeue() throw (QueueEmpty);
/**
* Retrieve the current number of items on the queue.
* @return the current number of items on the queue.
*/
size_t depth() const;
};
#endif // __LINKEDQUEUE_H__
/////////////////////// ////////////////////////////
//my.cpp
#include <iostream>
#include <string>
#include "linkedQueue.h"
using namespace std;
LinkedQueue::LinkedQueue()
{
front = NULL;
rear = NULL;
count = 0;
}
/**
* Enqueue a task onto the queue
* @param tsk The task to enqueue
* @throws QueueFull if there is not room on the queue to place the item.
*/
void LinkedQueue::enqueue(Task *tsk) throw (QueueFull)
{
NodeType* newNode;
newNode = new NodeType;
if (newNode == NULL)
{
throw QueueFull();
}
else
{
newNode->info = tsk;
newNode->next = NULL;
if (rear == NULL)
front = newNode;
else
rear->next = newNode;
rear = newNode;
count++;
}
}
/**
* Dequeue an element from the queue.
* @return the front of the queue.
* @throws QueueEmpty if there are no elements in the queue.
*/
Task LinkedQueue::*dequeue() throw (QueueEmpty)
{
if (front == NULL) {throw QueueEmpty();}
else
{
NodeType* tempPtr;
tempPtr = front;
item = front->info;
front = front->next;
if (front == NULL)
rear = NULL;
delete tempPtr;
LinkedQueue::count--;
return item;
}
}
/**
* Retrieve the current number of items on the queue.
* @return the current number of items on the queue.
*/
size_t LinkedQueue::depth() const
{
return count;
}
LinkedQueue::~LinkedQueue()
{
NodeType* tempPtr;
while (front != NULL)
{
tempPtr = front;
front = front->next;
delete tempPtr;
}
rear = NULL;
}
////////////////////////////////////////////////////////////////////////////////////////////
compile errors:
g++ -g -o linkedQueue.o -Wall -Werror -c linkedQueue.cpp
linkedQueue.cpp: In function ‘Task LinkedQueue::* dequeue()’:
linkedQueue.cpp:46: error: ‘front’ was not declared in this scope
linkedQueue.cpp:51: error: ‘item’ was not declared in this scope
linkedQueue.cpp:54: error: ‘rear’ was not declared in this scope
linkedQueue.h:31: error: invalid use of non-static data member ‘LinkedQueue::count’
linkedQueue.cpp:56: error: from this location
make: *** [linkedQueue.o] Error 1
欢迎堆栈溢出。如果你打算发布这样一个长长的问题和完全赋予你的任务的代码,没有人会有兴趣去看看它。相反,要确切地说明你到目前为止发现的问题以及你遇到的问题/问题。同时编辑帖子中的代码,只显示与您想要回答的特定问题相关的部分。 – Tuxdude 2013-02-27 06:22:20