ARC iOS Category for a NSArray and NSDictionary deep copy implementations

DeepCopy.h

//
//  DeepCopy.h
//
//

#import <Foundation/Foundation.h>

// Deep -copy and -mutableCopy methods for NSArray and NSDictionary

@interface NSArray (DeepCopy)

- (NSArray*) deepCopy;
- (NSMutableArray*) mutableDeepCopy;

@end

@interface NSDictionary (DeepCopy)

- (NSDictionary*) deepCopy;
- (NSMutableDictionary*) mutableDeepCopy;

@end

DeepCopy.m

//
// DeepCopy.m
//
//

#import "DeepCopy.h"


@implementation NSArray (DeepCopy)

- (NSArray*) deepCopy {
    unsigned int count = [self count];
    id cArray[count];
    
    for (unsigned int i = 0; i < count; ++i) {
        id obj = [self objectAtIndex:i];
        if ([obj respondsToSelector:@selector(deepCopy)])
            cArray[i] = [obj deepCopy];
        else
            cArray[i] = [obj copy];
    }
    
    NSArray *ret = [NSArray arrayWithObjects:cArray count:count];
    
    return ret;
}
- (NSMutableArray*) mutableDeepCopy {
    unsigned int count = [self count];
    id cArray[count];
    
    for (unsigned int i = 0; i < count; ++i) {
        id obj = [self objectAtIndex:i];
        
        // Try to do a deep mutable copy, if this object supports it
        if ([obj respondsToSelector:@selector(mutableDeepCopy)])
            cArray[i] = [obj mutableDeepCopy];
        
        // Then try a shallow mutable copy, if the object supports that
        else if ([obj respondsToSelector:@selector(mutableCopyWithZone:)])
            cArray[i] = [obj mutableCopy];
        
        // Next try to do a deep copy
        else if ([obj respondsToSelector:@selector(deepCopy)])
            cArray[i] = [obj deepCopy];
        
        // If all else fails, fall back to an ordinary copy
        else
            cArray[i] = [obj copy];
    }
    
    NSMutableArray *ret = [NSMutableArray arrayWithObjects:cArray count:count];
    
    return ret;
}

@end

@implementation NSDictionary (DeepCopy)

- (NSDictionary*) deepCopy {
    unsigned int count = [self count];
    id cObjects[count];
    id cKeys[count];
    
    NSEnumerator *e = [self keyEnumerator];
    unsigned int i = 0;
    id thisKey;
    while ((thisKey = [e nextObject]) != nil) {
        id obj = [self objectForKey:thisKey];
        
        if ([obj respondsToSelector:@selector(deepCopy)])
            cObjects[i] = [obj deepCopy];
        else
            cObjects[i] = [obj copy];
        
        if ([thisKey respondsToSelector:@selector(deepCopy)])
            cKeys[i] = [thisKey deepCopy];
        else
            cKeys[i] = [thisKey copy];
        
        ++i;
    }
    
    NSDictionary *ret = [NSDictionary dictionaryWithObjects:cObjects forKeys:cKeys count:count];

    return ret;
}
- (NSMutableDictionary*) mutableDeepCopy {
    unsigned int count = [self count];
    id cObjects[count];
    id cKeys[count];
    
    NSEnumerator *e = [self keyEnumerator];
    unsigned int i = 0;
    id thisKey;
    while ((thisKey = [e nextObject]) != nil) {
        id obj = [self objectForKey:thisKey];
        
        // Try to do a deep mutable copy, if this object supports it
        if ([obj respondsToSelector:@selector(mutableDeepCopy)])
            cObjects[i] = [obj mutableDeepCopy];
        
        // Then try a shallow mutable copy, if the object supports that
        else if ([obj respondsToSelector:@selector(mutableCopyWithZone:)])
            cObjects[i] = [obj mutableCopy];
        
        // Next try to do a deep copy
        else if ([obj respondsToSelector:@selector(deepCopy)])
            cObjects[i] = [obj deepCopy];
        
        // If all else fails, fall back to an ordinary copy
        else
            cObjects[i] = [obj copy];
        
        // I don't think mutable keys make much sense, so just do an ordinary copy
        if ([thisKey respondsToSelector:@selector(deepCopy)])
            cKeys[i] = [thisKey deepCopy];
        else
            cKeys[i] = [thisKey copy];
        
        ++i;
    }
    
    NSMutableDictionary *ret = [NSMutableDictionary dictionaryWithObjects:cObjects forKeys:cKeys count:count];
    
    return ret;
}

@end

Who holds the copyright on these and what license are these released under?

This is from stack overflow: https://stackoverflow.com/a/5453600/580487