C++:cout＜＜自定义类型输出

1.自定义类型

struct Student{
    int id;
    string name;
    Student();
    Student(int ID,string Name){
        id=ID;
        name=Name;
    }
    friend ostream & operator << (ostream &out,const Student &s)
    {
        out<<s.id<<":"<<s.name.c_str()<<endl;
        return out;
    }
} ;
typedef struct Student Student;      

重载<< 和>>即可实现输入输出,link=https://www.runoob.com/cplusplus/input-output-operators-overloading.html

必须要使用friend 友元函数

int main()
{ 
  typedef struct Student Student; 
  Student s1(1001,"萧海");
  cout<<s1;

  return 0;
}      

template<typename  T>
void print_vector(vector<T> v)
{
    typename vector<T>::iterator it;
    for(it=v.begin();it!=v.end();it++)
    {
        cout<<*it;
    }
    cout<<endl;
}      

vector<Student> b;
    b.push_back(*(new Student(1,"jsj")));
    b.push_back(*(new Student(2,"MSS")));
    b.push_back(*(new Student(3,"ZHL")));
//? where exactly the insert happend?
    b.insert(b.begin(),*(new Student(4,"HHH")));
    b.insert(b.end(),*(new Student(5,"LLL")));
    print_vector(b);      

4:HHH
1:jsj
2:MSS
3:ZHL
5:LLL