枚举 C++ 按索引获取

2021-12-29 00:00:00 enums c++

我想知道在 C++ 中是否有枚举可以访问第二个索引处的值吗?例如我有

I was wondering in C++ if I have an enum can I access the value at the second index? For example I have

enum Test{hi, bye};

如果我想要嗨",我可以做一些类似 Test[0] 的事情吗,谢谢.

if I want 'hi', can I do something like Test[0], thanks.

推荐答案

是和否.如果您的 Enum 没有明确的值,那么这是可能的.如果没有显式值,枚举值会按照声明的顺序给出 0-N 的数值.例如...

Yes and no. If your Enum does not have explicit values then it is possible. Without an explicit values, enum values are given numeric values 0-N in order of declaration. For example ...

enum Test {
  hi, // 0
  bye // 1
}

这意味着索引只是转换为文字值.

This means that indexes just translates into a literal value.

Test EnumOfIndex(int i) { return static_cast<Test>(i); }

这当然会在运行时进行 0 验证,一旦您添加显式值,它就会崩溃.但它会在默认情况下工作.

This of course does 0 validation at runtime and as soon as you add an explicit value it will break down. But it will work in the default scenario.

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