c++ - (C++) "No operator ">>"matches these operands"枚举

Question

所以，我完全是 c++ 语言的初学者，我正在做“通过游戏编程开始 C++”一书中的练习，特别是第 3 章的第一个练习。它要我创建一个“困难选择” Program"using std::cout 和 switch 语句，但是我在尝试使用 std::cin 输入变量时发现了一个问题(myDifficulty) 的枚举类型 difficulties，我在 >>> 下得到上面的错误。这是我的代码:

#include <iostream>

int main()
{
enum difficulties {EASY = 1, NORMAL, HARD, EXTREME};
difficulties myDifficulty;

std::cout << "Easy\nNormal\nHard\nExtreme\n";
std::cin >> myDifficulty;

switch (myDifficulty)
{
    case 1:
        std::cout << "You have chosen Easy as your difficulty." << std::endl;
        break;
    case 2:
        std::cout << "You have chosen Normal as your difficulty." << std::endl;
        break;
    case 3:
        std::cout << "You have chosen Hard as your difficulty" << std::endl;
        break;
    case 4:
        std::cout << "You have chosen Extreme as your difficulty. Good luck!" << std::endl;
        break;
}
system("pause");
return 0;

}

如果有人可以帮忙，谢谢。此外，如果我的代码有任何问题(它的外观等)，我们将不胜感激!

P.S 这是我的第一个问题。 :)

Answer 1

C++中enum类默认没有定义operator>>，需要自己创建operator:

std::istream& operator>> (std::istream& in, difficulties& diff) ;