enum or define, which one should I use?

Question

enum and #define appears to be able to do the same thing, for the example below defining a style. Understand that #define is macro substitution for compiler preprocessor. Is there any circumstances one is preferred over the other?

typedef enum {
    SelectionStyleNone,
    SelectionStyleBlue,
    SelectionStyleRed
} SelectionStyle;

vs

#define SELECTION_STYLE_NONE 0
#define SELECTION_STYLE_BLUE 1
#define SELECTION_STYLE_RED  2

Answer 1

Don't ever use defines unless you MUST have functionality of the preprocessor. For something as simple as an integral enumeration, use an enum.

Answer 2

An enum is the best if you want type safety. They are also exported as symbols, so some debuggers can display them inline while they can't for defines.

The main problem with enums of course is that they can only contain integers. For strings, floats etc... you might be better of with a const or a define.

Answer 3

The short answer is that it probably doesn't matter a lot. This article provides a pretty good long answer:

http://www.embedded.com/columns/programmingpointers/9900402?_requestid=345959