Why should I have an enumeration declared with a typedef in C++?

Question

I had code that looked like this:

enum EEventID {
  eEvent1,
  eEvent2,
  ...
  eEventN };

And that got reviewed and changed to

typedef enum {
  eEvent1,
  eEvent2,
  ...
  eEventN } EEventID;

What is the difference between the two? Why make the change? When I looked at this question, the only mention of typedefs got downvoted.

Answer 1

I found one possible answer here: "Well it is relevent to C language in which if you use an enum or structure which are user defined data types, you need to specify theenum or struct keyword while using it."

Maybe your reviewer is a hardcore C coder, and he does it automatically, out of habit.

Answer 2

The two are identical in C++, but they're not the same in C -- in C if you use the typedef you get code that is compatible between C and C++ (so can be used freely in a header file that might be used for either C or C++). That's the only reason I can see for preferring it.

Answer 3

Your reviewer doesn't know his C from his C++.

Answer 4

If there's a standard at the company, it could just be for consistency. Even if you never use in C, it's still better to do it the same way everywhere.

Answer 5

The typedef is superfluous in C++.
In C it is necessary if you want to define a variable of your enum type like so: EEventID event;, otherwise you would've had to specify it's an enum: enum EEventID event;.