C++ 重载 ++的代码

#define _CRT_SECURE_NO_WARNINGS
#include 
using namespace std;
class MyInteger
{
    friend ostream& operator<<(ostream& out, const MyInteger& myint);
    int m_Num;
public:
    MyInteger():m_Num(0) {};
    MyInteger& operator++()
    {
        m_Num++;
        return *this;
    }

    MyInteger operator++(int )//占位参数
    {
        MyInteger myint;
        myint.m_Num = m_Num;
        m_Num++;
        return myint;
    }

};
ostream& operator<<(ostream& out, const MyInteger& myint)
{
    out << myint.m_Num;
    return out;
}
int main()
{
  
    MyInteger myint;

    cout << ++(++myint) << endl;
    return 0;
}