C++流の大まかな運用

/* 
 * File:   main.cpp
 * Author: Vicky.H
 * Email:  [email protected]
 */
#include <iostream>
#include <fstream>
#include <sstream>
#include <cstring>

class A {
public:
    friend std::ostream& operator<<(std::ostream& os, const A& ref);
    friend std::istream& operator>>(std::istream& is, A& ref);

    A() { }

    A(const char* name, short age) : age(age) {
        strcpy(this->name, name);
    }
private:
    char name[21];
    short age;
};

std::ostream& operator<<(std::ostream& os, const A& ref) {
    os << ref.name << '
' /**     */ << ref.age;
    return os;
}

std::istream& operator>>(std::istream& is, A& ref) {
    is >> ref.name >> ref.age;
    return is;
}

/*
 * 
 */
int main(void) {
    //         
    std::ofstream ofs("./tmp.txt", std::ios::trunc | std::ios::binary);
    ofs << A("Lily", 25); //          
    ofs.flush();
    ofs.close();
    
    std::ifstream ifs("./tmp.txt", std::ios::in | std::ios::binary);
    A a2;
    ifs >> a2; //        ,       
    ifs.close();
    std::cout << a2 << std::endl;
    
    std::cout << "---------------------------" << std::endl;
    
    //         
    std::ostringstream oss; //            
    oss << A("string",99);
    oss.flush(); //        
    std::cout << oss.str() << std::endl;
    
    std::string str("test
123"); 
    std::istringstream iss(str); //             
    A a3;
    iss >> a3; //           
    iss.sync(); //        
    std::cout << a3 << std::endl;
    
    std::cout << "---------------------------" << std::endl;
    
    
    //         
    std::cout << A("Vicky", 25) << std::endl;
    A a;
    std::cout << "input A just like:
Vicky
25" << std::endl;
    std::cin >> a;
    std::cout << a << std::endl;

    std::cout << "---------------------------" << std::endl;

    
    return 0;
}

Lily
25
---------------------------
string
99
test
123
---------------------------
Vicky
25
input A just like:
Vicky
25
ooxx
1002
ooxx
1002
---------------------------