动态栈的实现(C++)

#include <iostream>
using namespace std;

const int STACKINCREMENT = 20;
const int STACK_INIT_SIZE = 10;

template <typename ElemType>
class MyOwnStack
{
    public:
        MyOwnStack();
        virtual ~MyOwnStack();
        int stackLen();
        void emptyStack();
        void realloc();
        void Push(ElemType);
        ElemType  Pop();
    protected:
        ElemType *base;
        ElemType *top;
        int stackSize;
};

template <typename ElemType>
MyOwnStack<ElemType>::MyOwnStack()
{
    base = new ElemType[STACK_INIT_SIZE];
    top = base;
    stackSize = STACKINCREMENT;
}

template <typename ElemType>
MyOwnStack<ElemType>::~MyOwnStack()
{
     delete[] base;
}

template <typename ElemType>
int MyOwnStack<ElemType>::stackLen()
{
     return top-base;
}

template <typename ElemType>
void MyOwnStack<ElemType>::emptyStack()
{
     top = base;
}

template <typename ElemType>
void MyOwnStack<ElemType>::realloc()
{
    ElemType* p = new ElemType[stackSize+STACKINCREMENT];
    ElemType* q = p;
    while(base!=top){
        *q = *base;
        q++;
        base++;
    }
    delete[] base;
    top = q;
    base = p;
    stackSize+=STACKINCREMENT;
}

template <typename ElemType>
void MyOwnStack<ElemType>::Push(ElemType e)
{
    if(top - base >= stackSize){
        realloc();
    }
    (*top) = e;
    top++;
}

template <typename ElemType>
ElemType MyOwnStack<ElemType>::Pop()
{
    if(top == base){
        cout<<"The Stack is empty.\n";
        exit(1);
    }
    return *--top;
}