C++重载输入输出操作符--Demo

#include <iostream>#include <string>using namespace std;class Fruit{private:string name;string colour;public:friend istream &operator >> (istream &,Fruit &);friend ostream &operator << (ostream &,const Fruit &);void print(){cout << colour <<" "<<name<<endl;}Fruit(const string &nst="apple",const string &cst="green"):name(nst),colour(cst){}~Fruit(){}};ostream &operator << (ostream &out, const Fruit &s){out << s.colour<<" "<<s.name;return out;}istream &operator >> (istream &in, Fruit &s){in >> s.colour >> s.name;if(! in){cerr << "Wrong input !"<<endl;}return in;}int main(){Fruit apple;cout << apple;return 0;}