// 产生仿函数实体

equal_to<int> equal_to_obj;

not_equal_to<int> not_equal_to_obj;

greater<int> greater_obj;

greater_equal<int> greater_equal_obj;

less<int> less_obj;

less_equal<int> less_equal_obj;

// 使用对象完成函数功能

cout << equal_to_obj(3, 5) << endl;

cout << not_equal_to_obj(3, 5) << endl;

cout << greater_obj(3, 5) << endl;

cout << greater_equal_obj(3, 5) << endl;

cout << less_obj(3, 5) << endl;

cout << less_equal_obj(3, 5) << endl;

// 直接使用仿函数的临时对象完成函数功能

cout << equal_to<int>()(3, 5) << endl;

cout << not_equal_to<int>()(3, 5) << endl;

cout << greater<int>()(3, 5) << endl;

cout << greater_equal<int>()(3, 5) << endl;

cout << less<int>()(3, 5) << endl;

cout << less_equal<int>()(3, 5) << endl;

}