警告修复后将初始化

晚上好（感恩节快乐），

我有以下代码（从我的主代码中删除到独立文件中），并且正在收到一些我想解决的警告消息。

这是代码：

#include <cassert>
#include <ostream>
#include <climits>
#include <iostream>
#include <string>
using namespace std;
class WordCount
{
public:
   // Constructors
   WordCount() : word(""), count(0) { }
   WordCount(string theWord, unsigned theCount = 1) : word(theWord), count(theCount) { }
   // Accessors
   string Word() const { return word; }
   unsigned Count() const { return count; }
   // Mutator
   void Update() { ++count; }
   // Output a Word to a stream.
   void Show(ostream &os)  { os << word << "=" << count; }
   // Overloaded relational operators
    bool operator<(WordCount &rhs) { return word < rhs.word; }
    bool operator>(WordCount &rhs) { return word > rhs.word; }
    bool operator==(WordCount &rhs) { return word == rhs.word; }
    bool operator<=(WordCount &rhs) { return word <= rhs.word; }
    bool operator>=(WordCount &rhs) { return word >= rhs.word; }
    bool operator!=(WordCount &rhs) { return word != rhs.word; }
private:
   string   word;    // The word to be counted
   unsigned count;   // The number of occurrences
};
class Queue 
{
private:
    struct Node
    {
        WordCount data; //data in node
        Node *next;     //pointer to next node
        // Default Constructor
        Node() : next(0) {}
        // Explicit Constructor
        Node(const WordCount &theData, Node *const theNext = 0)
            : data(theData), next(theNext) { }
    };
public: 
    Queue() : head(0), tail(0) {}               
    bool Empty() const { return head == 0; }    
    void Enqueue(const WordCount &elem);            
    WordCount Dequeue();                            
    WordCount Head() { return head->data; }
private:
    Node *tail;     // "end" of queue
    Node *head;
};
void Queue::Enqueue(const WordCount &elem)
{
    Node* temp = new(nothrow) Node(elem);
    assert(temp != NULL);
    // head == tail if head == NULL, so must also be assigned temp
    if (head == NULL)
        head = temp;
    // add temp after current tail
    else
        tail->next = temp;
    // update tail adress to be new temp node
    tail = temp;
}
WordCount Queue::Dequeue()
{
    assert (!Empty());
    WordCount poppedData = head->data;
    Node *temp = head;
    head = head->next;
    if (head == NULL) 
        tail = NULL;
    delete temp;   
    return poppedData;
}
int main()
{
    return 0;
}

当我做G test.cpp -wall时，我会收到以下警告

test.cpp: In constructor 'Queue::Queue()':
test.cpp:61:8: warning: 'Queue::head' will be initialized after [-Wreorder]
  Node *head;
        ^
test.cpp:60:8: warning:   'Queue::Node* Queue::tail' [-Wreorder]
  Node *tail;  // "end" of queue
        ^
test.cpp:54:2: warning:   when initialized here [-Wreorder]
  Queue() : head(0), tail(0) {}

我有没有办法重写/重新编写代码以保持其功能并删除这些警告？我根本不熟悉此警告，并且一直在阅读它，但是仅凭我很难遵循许多代码示例，更不用说理解解决方法的方法了。

任何建议将不胜感激，谢谢。