How do I check if one of multiple macros is defined in a single #ifdef?

Question

I have some C++ code, and want to perform an action if the __APPLE__ or __linux macros are defined.

If I did it as a normal if conditional, it would be easy using ||:

if (something || something) { .. code .. }

But as of what I know there is no || operator for #ifdef statements. How would I check if __APPLE__ or __linux is defined using a single #ifdef statement?

Well, if thinking "available on OS X/iOS and Linux", don't you want to check for POSIX-availablity instead? — , May 04 '13 at 20:41
Possible duplicate of [how to use #ifdef with an OR condition?](https://stackoverflow.com/questions/9682593/how-to-use-ifdef-with-an-or-condition) — Itay Grudev, May 09 '19 at 19:51

score 34 · Accepted Answer · answered May 04 '13 at 20:39

34

You can't in a single #ifdef would a single #if do instead?

#if defined(__APPLE__) || defined(__linux)

this also works if you prefer

#if defined __APPLE__ || defined __linux

answered May 04 '13 at 20:39

john

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score 3 · Answer 2 · answered May 04 '13 at 20:41

3

In my C++ there is.

#if defined(__APPLE__) || defined(__linux)
  // ...
#endif

answered May 04 '13 at 20:41

masoud

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How do I check if one of multiple macros is defined in a single #ifdef?

2 Answers2

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