Helpful Obj-C macroses

Prefix.pch

#define IS_IPHONE UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone
#define IS_IPAD   UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad

#define SYSTEM_VERSION_COMPARE(v) [[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch]

#define IS_OS_EQUAL(v)             (SYSTEM_VERSION_COMPARE(v) == NSOrderedSame)
#define IS_OS_GREATER(v)           (SYSTEM_VERSION_COMPARE(v) == NSOrderedDescending)
#define IS_OS_GREATER_OR_EQUAL(v)  (SYSTEM_VERSION_COMPARE(v) != NSOrderedAscending)
#define IS_OS_LESS(v)              (SYSTEM_VERSION_COMPARE(v) == NSOrderedAscending)
#define IS_OS_LESS_OR_EQUAL(v)     (SYSTEM_VERSION_COMPARE(v) != NSOrderedDescending)

#ifdef DEBUG
#define DebugLog(format, ...) NSLog(format, ##__VA_ARGS__)
#define DebugLogIfError(error, reason) if (error) NSLog(@"%@%@\n%@\n%@", (reason ? reason : @""), error, [error userInfo], [error localizedDescription])
#else
#define DebugLog(...)
#define DebugLogIfError(...)
#endif

#define safe_block(block, ...) if (block) block(__VA_ARGS__)

#define safe_value(value, default) (value ?: default)
#define safe_string(value) safe_value(value, @"")