在单独的枚举类型中重用枚举值 [英] Reusing enum values in separate enum types

问题描述

有没有办法在单独的类型中重用相同的枚举值？我希望能够执行以下操作：

Is there a way to reuse the same enum value in separate types? I'd like to be able to something like the following:

enum DeviceState { UNKNOWN, ACTIVE, DISABLED, NOTPRESENT, UNPLUGGED };
enum DeviceType { UNKNOWN, PLAYBACK, RECORDING };

int _tmain(int argc, _TCHAR* argv[])
{
    DeviceState deviceState = DeviceState::UNKNOWN;
    DeviceType deviceType = DeviceType::UNKNOWN;
    return 0;
}

这对我来说很有意义，但对C ++编译器却不行，它抱怨： 错误C2365：未知：重新定义；先前的定义是上述第2行中的枚举数 。有没有这样做的正确方法，还是应该始终使用唯一的枚举值？我无法想象这总是可以保证是否包含其他人的代码。

This makes sense to me, but not to the C++ compiler- it complains: error C2365: 'UNKNOWN' : redefinition; previous definition was 'enumerator' on line 2 of the above. Is there a correct way of doing this, or am I supposed to always use unique enum values? I can't imagine this is always possible to guarantee if I'm including someone else's code.

推荐答案

您可以并且应该，将您的枚举包含在命名空间中：

You can, and should, include your enums in a namespace:

namespace DeviceState
{
    enum DeviceState{ UNKNOWN, ACTIVE, DISABLED, NOTPRESENT, UNPLUGGED };
}
namespace DeviceType
{
    enum DeviceType{ UNKNOWN, PLAYBACK, RECORDING };
}

//...

DeviceType::DeviceType x = DeviceType::UNKNOWN;

这篇关于在单独的枚举类型中重用枚举值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！