c++ - 我需要使用枚举来表示难度级别。我一直收到有关使用 cin>> 的错误消息

Question

我必须使用枚举来表示难度级别。这是代码。

// Menu Chooser
// Demonstrates the switch statement

    #include <iostream>
    #include <string>
    using namespace std;

    int main() 
    {
        cout << "Difficulty Levels\n\n";
        cout << "1 - Easy\n";
        cout << "2 - Normal\n";
        cout << "3 - Hard\n\n";

        enum userChoice {Easy, Normal, Hard};
        userChoice choice;
        cout << "Choice: ";
        cin >> choice;

        switch (choice)
        {
        case 1: 
                cout << "You picked Easy.\n";
                break;
        case 2: 
                cout << "You picked Normal.\n";
                break;
        case 3: 
                cout << "You picked Hard.\n";
                break;
        default:
                cout << "You made an illegal choice.\n";
        }

        return 0;
    }

和错误信息:

error C2678: binary '>>' : no operator found which takes a left-hand operand of type 'std::istream' (or there is no acceptable conversion)

Answer 1

>> 运算符没有默认实现来获取输入并将其映射到 enum。您需要将 int 作为输入，然后将其映射到 enum。或者，您可以为 >>> 运算符编写一个重载，将输入映射到您的枚举。

当然，查看您的代码，您似乎没有将定义的枚举用于任何事情。也许您可以删除它并改用 int？