C++ 中的 64 位枚举? [英] 64 bit enum in C++?

问题描述

有没有办法在 C++ 中使用 64 位枚举?在重构一些代码时，我遇到了一堆 #defines，它们作为枚举会更好，但大于 32 位会导致编译器出错.

Is there a way to have a 64 bit enum in C++? Whilst refactoring some code I came across bunch of #defines which would be better as an enum, but being greater than 32 bit causes the compiler to error.

出于某种原因，我认为以下可能有效:

For some reason I thought the following might work:

enum MY_ENUM : unsigned __int64  
{  
    LARGE_VALUE = 0x1000000000000000,  
};

推荐答案

我认为 C++98 不可能做到这一点.枚举的底层表示取决于编译器.在这种情况下，您最好使用:

I don't think that's possible with C++98. The underlying representation of enums is up to the compiler. In that case, you are better off using:

const __int64 LARGE_VALUE = 0x1000000000000000L;

从 C++11 开始，可以使用枚举类来指定枚举的基类型:

As of C++11, it is possible to use enum classes to specify the base type of the enum:

enum class MY_ENUM : unsigned __int64 {
    LARGE_VALUE = 0x1000000000000000ULL
};

此外，枚举类引入了一个新的名称范围.因此，不是引用 LARGE_VALUE，而是引用 MY_ENUM::LARGE_VALUE.

In addition enum classes introduce a new name scope. So instead of referring to LARGE_VALUE, you would reference MY_ENUM::LARGE_VALUE.

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