根据用户选择从类模板中定义对象并解决本地定义对象的范围-新问题

我正在使用两个堆栈实现一个队列。整个代码基于模板，以支持多种数据类型。

#include <iostream>
#define STACKSIZE 100

template <class T>
class Stack
{
private:
    int top;
    T *nodes;
public:
    Stack();
    T gettop();
    bool empty();
    void push(T&);
    T pop();
    ~Stack();
};

template <class T>Stack<T>::Stack()
{
    top=-1;
    nodes=new T[STACKSIZE];
}

template <class T>Stack<T>::~Stack()
{
    delete nodes;
}

template <class T> bool Stack<T>::empty()
{
    return(top<0);
}

template <class T> void Stack<T>::push(T&j)
{
    if(top==STACKSIZE-1)
    {
        std::cout<<"Stack Overflow"<<std::endl;
        return;
    }
    nodes[++top]=j;
}

template <class T>T Stack<T>::pop()
{
    T p;
    if (empty())
    {
        std::cout<<"Stack Underflow"<<std::endl;
        return p;
    }
    p=nodes[top--];
    return p;
}

template <class T>T Stack<T>::gettop()
{
    return this->top;
}

template <class T>
class Queue
{
    Stack<T>s1;
    Stack<T>s2;
public:
    void insert_into_queue(T data)
    {
        s1.push(data);
        std::cout<<"The value: "<<data<<" has been inserted into the Queue"<<std::endl;
    }
    void delete_from_queue()
    {
        if(s1.empty())
        {
            std::cout<<"The Stack S1 is Empty which implies Queue is Empty, nothing to delete"<<std::endl;
            return;
        }
        while(!s1.empty())
        {
            T top=s1.gettop();
            s1.pop();
            s2.push(top);
        }
        T d_val;
        d_val=s2.gettop();
        s2.pop();
        std::cout<<"The value: "<<d_val<<" has been deleted from the Queue"<<std::endl;
        while(!s2.empty())
        {
            T top=s2.gettop();
            s2.pop();
            s1.push(top);
        }
    }
};

int main()
{
    char choice;
    int option;
    int val;
    while(1)
    {
    std::cout<<"Provide the choice of DATA to work on: I for Integer, F for float, C for Character"<<std::endl;
    std::cin>>choice;
        if (choice == 'I' || choice == 'i')
        {
            Queue<int> q;
            break;
        }
        else if (choice == 'F' || choice == 'f')
        {
            Queue<float> q;
            break;
        }
        else if (choice == 'C' || choice == 'c')
        {
            Queue<char> q;
            break;
        }
        else
        {
            std::cout << "Not a valid choice" << std::endl;
        }
    }
    while(1)
    {
        std::cout<<"#######################################################################################"<<std::endl;
        std::cout<<"Press 1 to Insert a value into Queue: "<<std::endl;
        std::cout<<"Press 2 to Delete a value into Queue: "<<std::endl;
        std::cout<<"Press 3 to Exit the Program"<<std::endl;
        std::cin>>option;
        switch(option)
        {
            case 1:
                std::cout<<"Insert the value: "<<std::endl;
                std::cin>>val;
                q.insert_into_queue(val);
                break;
            case 2:
                q.delete_from_queue();
                break;
            case 3:
                exit(0);
                break;
            default:
                std::cout<<"Selected Option is Invalid"<<std::endl;
        }
    }
    return 0;
}

我的问题是我想从用户那里选择一个选项来指定队列的数据类型，直到用户为队列值提供正确的输入为止。

然后，我希望用户将数据插入队列或从队列中删除数据或从程序中退出。

我试图在main（）函数内部使用两个无尽的while（1）循环拉动它们，但是当我这样做时，我松开了q的范围。

请建议对代码进行适当的修改（或修改代码以实现所需的功能）。

这个问题与在以下意义上提到的其他问题不同

1. 我无法为队列创建基类，因为在这种情况下我无法定义成员

 Stack<T>s1;
 Stack<T>s2;

和方法

 void insert_into_queue(T data)
    {
        s1.push(data);
        std::cout<<"The value: "<<data<<" has been inserted into the Queue"<<std::endl;
    }
    void delete_from_queue()
    {
        if(s1.empty())
        {
            std::cout<<"The Stack S1 is Empty which implies Queue is Empty, nothing to delete"<<std::endl;
            return;
        }
        while(!s1.empty())
        {
            T top=s1.gettop();
            s1.pop();
            s2.push(top);
        }
        T d_val;
        d_val=s2.gettop();
        s2.pop();
        std::cout<<"The value: "<<d_val<<" has been deleted from the Queue"<<std::endl;
        while(!s2.empty())
        {
            T top=s2.gettop();
            s2.pop();
            s1.push(top);
        }
    }

这完全取决于模板。

另外，如果条件满足，q会在本地定义

 if (choice == 'I' || choice == 'i')
        {
            Queue<int> q;
            break;
        }

现在如何解决q的范围

 case 1:
                std::cout<<"Insert the value: "<<std::endl;
                std::cin>>val;
                q.insert_into_queue(val);
                break;

可以实现。