简单顺序栈（C++模版技术实现）

下面代码仅供本人复习数据结构所用，实用性N低，各位飘过吧~~哈哈:>

//
// C++ 模版技术实现简单顺序栈. 
// 
 
#include <cstdlib>
#include <iostream>
#include <iomanip>
#include <stdexcept>
 
//
// 顺序栈类模版.  
//
template <typename T>
class Stack
{
private:
    int _top;
    size_t _size;
    T *_pStack;
    static const size_t _DEF_SIZE = 20;
    // 
    // _MIN_TOP 不应为 size_t 类型.
    // 因为 size_t 类型与 int 类型变量比较时会将 int 类型转换为 size_t 类型. 
    //
    static const int _MIX_TOP = 0; 
     
public:
    Stack(const size_t size = _DEF_SIZE)
        : _top(_MIX_TOP - 1)
        , _size(size)
    { _pStack = new T[_size]; }
     
     
    ~Stack(void)
    { delete[] _pStack; }
     
     
    bool isEmpty(void) const
    { return _MIX_TOP > _top; }
     
     
    bool isFull(void) const
    { return _size - 1 == _top; }
     
     
    T getTop(void) const
    {
        if (isEmpty()) {
            throw std::underflow_error("栈空下溢 !"); 
        }
        return _pStack[_top]; 
    }
     
     
    void push(const T &val)
    {
        if (isFull()) {
            throw std::overflow_error("栈满上溢 !");
        }
        _pStack[++_top] = val;
    }
     
     
    T pop(void)
    { 
        if (isEmpty()) {
            throw std::underflow_error("栈空下溢 !");
        }
        return _pStack[_top--];
    }
};
 
//
// 测试栈. 
// 
int main(void)
{
    const size_t MAX_SIZE = 20;
    Stack<int> stack(MAX_SIZE);
     
    std::cout << "栈" << (stack.isEmpty() ? "" : "不") << "为空." << std::endl; 
    std::cout << "栈" << (stack.isFull() ? "" : "不") << "为满." << std::endl; 
     
    for (size_t i = 0; i < MAX_SIZE; ++i)
    {
        stack.push(i);
        std::cout << std::setw(3) << stack.getTop();
    }
    // stack.push(MAX_SIZE);
     
    std::cout << std::endl;
    std::cout << "栈" << (stack.isEmpty() ? "" : "不") << "为空." << std::endl; 
    std::cout << "栈" << (stack.isFull() ? "" : "不") << "为满." << std::endl; 
     
    for (size_t i = 0; i < MAX_SIZE; ++i)
    {
        std::cout << std::setw(3) << stack.pop();
    }
    // std::cout << std::setw(3) << stack.pop();
     
    return EXIT_SUCCESS;
}