C中更好的枚举（Arduino）

Question

I thought the below was a neat way to implement enums in C.

struct states
{
  enum
  {
    waitPackage,
    waitReference,
    waitData
  };

}state;

This adds some type safety and I can also acces each member through state.XXX which I think is a lot more neat than prepend all the names of the enum items, and access the members in a fashion like state_XXX. Or what do you think, have I missed something?

However, I cant use the enum above in a switch-case statement as the compiler says that state isn't a constant. Is there a way to tell the compiler that I don't intend to change the members of the enum ot it could be used in switch-case? Or another way to accomplish what I would like here?

In a C++ I solved it by placing the enums in namespaces but thats a not an option here.

Answer 1

Types in C are always global and never nested. So there is no way to have scoped constants.

Thus the :: notation is not allowed in C, it is not part of the syntax. Eg your constants as waitPackage are visible as such everywhere.