How to add a 'or' condition in #ifdef

Question

How can I add a \'or\' condition in #ifdef ?

I have tried:

#ifdef CONDITION1 || CONDITION2

#endif

Answer 1

#if defined(CONDITION1) || defined(CONDITION2)

should work. :)

#ifdef is a bit less typing, but doesn't work well with more complex conditions

Answer 2

May use this-

#if defined CONDITION1 || defined CONDITION2
//your code here
#endif

This also does the same-

#if defined(CONDITION1) || defined(CONDITION2)
//your code here
#endif

---

Further-

• AND: #if defined CONDITION1 && defined CONDITION2
• XOR: #if defined CONDITION1 ^ defined CONDITION2
• AND NOT: #if defined CONDITION1 && !defined CONDITION2

Answer 3

I am really OCD about maintaining strict column limits, and not a fan of "\" line continuation because you can't put a comment after it, so here is my method.

//|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|//
#ifdef  CONDITION_01             //|       |//
#define             TEMP_MACRO   //|       |//
#endif                           //|       |//
#ifdef  CONDITION_02             //|       |//
#define             TEMP_MACRO   //|       |//
#endif                           //|       |//
#ifdef  CONDITION_03             //|       |//
#define             TEMP_MACRO   //|       |//
#endif                           //|       |//
#ifdef              TEMP_MACRO   //|       |//
//|-  --  --  --  --  --  --  --  --  --  -|//

printf("[IF_CONDITION:(1|2|3)]\n");

//|-  --  --  --  --  --  --  --  --  --  -|//
#endif                           //|       |//
#undef              TEMP_MACRO   //|       |//
//|________________________________________|//