C++ Have array values in an enum?

Question

I was wondering if it is possible to have an array value in an enum? Example

    enum RGB {
      RED[3],
      BLUE[3]

    } color;

That way RED could contain values of (255,0,0) since that is the RGB color code for red.

Answer 1

No you can't do that with an enum. It looks a lot like you want a class/struct:

class Color {
public:
    int red;
    int green;
    int blue;

    Color(int r, int g, int b) : red(r), green(g), blue(b) { }
};

Once you have that class defined, you can then put it into a container (eg array, vector) and look them up. You could use an enum to refer to elements in an array, for example.

enum PresetColor {
    PRESET_COLOR_RED,
    PRESET_COLOR_GREEN,
    PRESET_COLOR_BLUE,
};

...
Color presetColors[] = { Color(255, 0, 0), Color(0, 255, 0), Color(0, 0, 255) };

Color favouriteColor = presetColors[PRESET_COLOR_GREEN];

With that in mind, you could wrap all this up to be more maintainable, but I would say that's out of the scope of this question.

Answer 2

You cannot do that. The tokens in an enum can only hold integral values.

A possible solution:

struct Color {uint8_t r; uint8_t g; uint8_t b;}; 

Color const RED = {255, 0, 0};
Color const GREEN = {0, 255, 0};
Color const BLUE = {0, 0, 255};

Answer 3

长话短说：不，这是不可能的。

Answer 4

不，枚举的定义只允许它们保存整数值。