C++ Hide enum class from rest of code

Asked Jun 19 '17 at 20:54

Active Jun 19 '17 at 22:24

Viewed 300 times

I have some code with an enum class in it. I only want there to exist a single instance of this enum class. I am aware of singleton classes, but is there a way to make an enum class only visible from within the current file?

Trivial example:

enum class StateInstanceOption
{
    STATE_INSTANCE_A,
    STATE_INSTANCE_B
}gCurrentState{StateInstanceOption::STATE_INSTANCE_A}; // global variable to hold current state "pointer" (really a flag)

Obviously the user need to be able to read/write gCurrentState, but I don't want the user to be able to create more instances of StateInstanceOption.

Is this possible?

To clarify, I don't want the user to be able to create another instance of StateInstanceOption, but I do want them to be able to see gCurrentState.

edited Jun 19 '17 at 22:24

asked Jun 19 '17 at 20:54

FreelanceConsultant

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Did I miss the new C standard making C C++? If not: don't spam tags! – too honest for this site Jun 19 '17 at 20:58
Make it `static` or put it in an unnamed namespace? Thus making it available to the current compilation unit only.? – Jesper Juhl Jun 19 '17 at 21:11
I'm quite surprised this compiles, but it does. It is however undreadable. – Michaël Roy Jun 19 '17 at 21:18
Why on earth would you want this? Behind the scenes, an enum is just an integer... How would you access (read) `gCurrentState` after all? You couldn't assign to it, if only a single "instance" was present, wouldn't you? – Daniel Jour Jun 19 '17 at 21:50
@DanielJour `gCurrentState` would be read in the current file only. – FreelanceConsultant Jun 19 '17 at 21:57

C++ Hide enum class from rest of code

0 Answers0