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December 19, 2015 17:19
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Objective-C macro for switching on objects
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@implementation NSObject (Extra) | |
- (BOOL)isEqualToAnyOf:(id)object, ... | |
{ | |
va_list args; | |
va_start(args, object); | |
for (id other = object; other != nil; other = va_arg(args, id)) { | |
if ([self isEqual:other]) return YES; | |
} | |
va_end(args); | |
return NO; | |
} | |
@end | |
#define SWITCH(object, ...) { \ | |
id ___switch_object = object; \ | |
BOOL ___switch_stop = NO; \ | |
do __VA_ARGS__ while(0); \ | |
} | |
#define CASE(...) \ | |
if (___switch_stop) break; \ | |
if ([___switch_object isEqualToAnyOf:__VA_ARGS__, nil] && (___switch_stop = YES)) | |
#define DEFAULT \ | |
if (___switch_stop) break; | |
void Test(NSString *string) { | |
SWITCH(string, { | |
CASE(@"Great success") { | |
// Switch cases auto-break so you don't have to | |
} | |
CASE(@"Returning from inside a case works just fine") { | |
return; | |
} | |
CASE(@"I", @"like", @"turtles") // Match on any of the passed | |
// Single statements can be left without braces | |
thatsCool(); | |
DEFAULT { | |
NSLog(@"Default case reached"); | |
} | |
}); | |
} |
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