Number of elements in an enum

Question

In C, is there a nice way to track the number of elements in an enum? I\'ve seen

enum blah {
    FIRST,
    SECOND,
    THIRD,
    LAST
};

Answer 1

Old question, I know. This is for the googlers with the same question.

You could use X-Macros

Example:

//The values are defined via a map which calls a given macro which is defined later
#define ENUM_MAP(X) \
      X(VALA, 0)    \
      X(VALB, 10)   \
      X(VALC, 20)

//Using the map for the enum decl
#define X(n, v) [n] = v,
typedef enum val_list {
    ENUM_MAP(X) //results in [VALA] = 0, etc...
} val_list;
#undef X

//For the count of values
#define X(n, v) + 1
int val_list_count = 0 + ENUM_MAP(X); //evaluates to 0 + 1 + 1 + 1
#undef X

This is also transparent to an IDE, so auto-completes will work fine (as its all done in the pre-processor).