用户自定义类型的输入输出--I/O of User-Defined Types

#include 
#include <string>
using namespace std;

struct Entry {
    string name;
    int number;
};

ostream& operator<<(ostream& os, const Entry& e)
{
    return os << "{\"" << e.name << "\"," << e.number << "}";
}

istream& operator>>(istream& is, Entry& e)
//read {"name",number}pair.Note:formatted with{"",and}
{
    char c, c2;
    if (is >> c && c == '{' && is >> c2 && c2 == '"') {   //start with a {"
        string name;                                      //the default value of string is the empty string:""
        while (is.get(c) && c != '"')                     //anything before a " is part of the name
            name += c;

        if (is >> c && c == ',') {

            int number = 0;

        if (is >> number >> c && c == '}') {              //read the number and a }

            e = { name,number };                          //assign to the entry
            return is;
            }
        }
    }
    is.setf(ios_base::failbit);                           //register the failure in the stream
    return is;
}

int main()
{
    for (Entry ee; cin >> ee;)                            //read from cin into ee
        cout << ee << '\n';                               //write ee to cout
    return 0;
}