Using #ifdef doesn't work with Unreal Header Tool

[anonymous_user_86746194]

You don’t need the defined keyword. If it is not defined it is falsy.

You are doing the equivalent of this in the macro world:

if (I  < 5 || 10 || 17)

This is an illegal statement. The code you want is:

#if __cplusplus || UE_GAME || UE_EDITOR || UE_SERVER