简单的i++ ++i实现

#include <iostream>
using namespace std;
class INT
{   
    public:
      friend ostream& operator<<(ostream& os, const INT& i);    

      INT(int i) : m_i(i) {};

      INT& operator++()
      {
        ++(this->m_i);
        return *this;
      }

      const INT operator++(int)
      {
        INT temp = *this;
        ++(*this);
        return temp;
      }

      const INT operator--()
      {
        --(this->m_i);
        return *this;
      }

      const INT operator--(int)
      {
        INT temp = *this;
        --(*this);
        return temp;
      }

      int& operator*() const
      {
        return (int&)m_i;
      }

    private:
      int m_i;
};      


ostream& operator<<(ostream& os, const INT& i)
{
    os<< ‘[‘<<i.m_i<< ‘]‘;
    return os;
}

int main()
{
    INT I(5);
    cout<<I++<<endl;   //operator++(int)
    cout<<++I<<endl;
    cout<<I--<<endl;
    cout<<--I<<endl;
    cout<<*I<<endl;
    return 0;
}

运行结果：