I was looking at Apple\'s Lister (for Apple Watch, iOS, and OS X) sample. The sample performs a test for iOS and OS X:
#import
#if
As of watchOS 2.0, you can run native code on the watch, so this is a more relevant question.
I'm using the first early beta of watchOS 2, so this may change, but right now, TARGET_OS_WATCH
is set to 1 on watchOS.
(Also, be careful: TARGET_OS_IPHONE
is also set to 1 on watchOS, though TARGET_OS_IOS
is 0.)