Macro condition for iOS and OSX code

Question

I need to support iOS and OSX in my shared library, whats the best Macro / Practise for conditioning iOS and OSX code

the bellow code doesn't work for some reason :/

- (NSString *)hostName {
    #ifdef TARGET_OS_IPHONE
        return [[UIDevice currentDevice] name];
    #elif TARGET_OS_MAC
        return [[NSHost currentHost] localizedName];
    #endif
}

Answer 1

Two issues:

1. Use #if rather than #ifdef
2. Check TARGET_OS_IPHONE first since TARGET_OS_MAC is defined to 1 for both platforms

See: Which conditional compile to use to switch between Mac and iPhone specific code?