Best way to create "modes"

[felipe21]

Hello,
I am writing an app and I was wondering how can I implement
"mode" constants, like the openGl's GL_*, for example, I need for a part
of my program the constants BUTTON_PRESSED, BUTTON_RELEASED, etc, for another
NEXT_CARD, PREVIOUS_CARD and so on. The ideas I came up with were

*create only one enum of modes and put in a header to include where necessary
*create several enums, one for each header
*use #define CONSTANT either in one header file to include or in each header file
separately

So which is the best practice, if any?

Thanks in advance.

[Disch]

It depends exactly on how these modes are to be used.

I would lean in favor of typed enums for different practices. OpenGL does plain #defines, which makes it vulnerable to misuse. IE, you can pass any mode to any function which takes a mode, even if it makes no sense.

For your particular instance, I would recommend something like:

enum BUTTONSTATE
{
  BUTTON_PRESSED,
  BUTTON_RELEASED
};

enum CARD  // come up with a better name for this probably
{
  NEXT_CARD,
  PREV_CARD
};

//etc 

This way you can't accidentally pass 'BUTTON_PRESSED' to a function which takes a 'CARD' (or something similar) because the compiler will bark at you.

[felipe21]

Thanks for your reply. I see your point. In this case I would
make these enums members of the respective classes ?

[Disch]

That's what I do.