运算符重载，左移运算符

class myclass {
public:
	myclass(string name = "", int age = 0) :name(name), age(age) {}

	void print()
	{
		cout << name << ":" << age << endl;
	}
	friend myclass operator+(myclass object1, myclass object2);
	//类的成员函数重载
	myclass operator-(myclass object1)
	{
		return myclass(this->name, age - object1.age);;
	}
	friend std::ostream& operator<<(std::ostream& stream, const myclass& other);
	friend std::istream& operator>>(std::istream& istream, myclass& thiso);
private:
	string name;
	int age;
};