why need typedef in the C++ enum definition [duplicate]

Question

I saw the following in the header file

typedef enum Test__tag {
    foo,
    bar
} Test;

I am wondering why using typedef; I can just use

enum Test{
    foo,
    bar
};

is that right?

Answer 1

It's for C users. Basically when you go the typedef way, in C you can say

Test myTest;

whereas when you just used enum Test, you'd have to declare a variable like this:

enum Test myTest; 

It's not needed if only C++ is used though. So it might also just be written by a C programmer who is used to this style.

Answer 2

Yes, in C++ you declare x without the typdef just by writing

 enum Test{
    foo,
    bar
};
Test x;

However if you were to try the same thing in C you would need to declare x as

 enum Test x;

or use the typedef.

So the the typedef is probably a habit left over from C (unless the header file is in fact C).