关于 C++ 中 this 指针的使用~

#include<iostream>
#include<string>
using namespace std;

class student
{
private:
    int num;
    string name;
    float grade;
public:
    student();
    void put(student *this);
};

student::student()
{
num=0;
name="none";
grade=0;
}

void student::put(student *this)
{
cout<<this->num<<endl;
cout<<this->name<<endl;
cout<<this->grade<<endl;
}

void main()
{
student stu;
stu.put(&stu);
}

本想用此程序来验证一下this指针的用法的，却无论如何都无法运行~请问哪儿出了错？