[C++笔记]左移运算符重载错误分析 [Error]no match for ‘operator＜＜‘无匹配的左移运算符

#ifndef STUDENT_H
#define STUDENT_H
#include
#include 
//#include 
using namespace std;
class Student
{

public:
    Student(string name = "",int age = 0);
  friend ostream &operator<< (const Student &v,ostream &out)
  {
      out << "姓名" << v.m_name << "t年龄" << v.m_age ;
      return out;
  }
    string m_name;
    int m_age;
};

#endif // STUDENT_H

应改为： friend ostream &operator<< (ostream &out,const Student &v)

容器：

     vector v;
    v.push_back(Student("xix",18));
    v.push_back(Student("luc",13));
    v.push_back(Student("alice",15));
    for(int i = 0;i < v.size();i++)
    {
        //cout << "姓名" << v[i].m_name << "t年龄" << v[i].m_age << endl;
        cout << v[i] << endl;
    }