For X in Y with C do {}

BlockHacking

#import "BlockHacking.h"
typedef void (^twoObjectBlock)(id a, id b);
typedef void (^XYZBlock)(Class x, NSArray *y, id c, twoObjectBlock b);

XYZBlock arrayDoBlock = ^(Class x, NSArray *y, id c, twoObjectBlock b) {
    for (x in y) {
        b(c,x);
    }
};

@implementation BlockHacking

+ (void)hackBlocks {
    NSMutableArray *mutableArray = [NSMutableArray array];
    
    NSArray *fooArray = [NSArray arrayWithObjects:@"alpha", @"beta", @"gamma", @"delta", @"epsilon", nil];
    twoObjectBlock logAndStoreBlock = ^(id a, id b) {
        NSLog(b);
        [(NSMutableArray *)a addObject:b];
    };
    
    arrayDoBlock([NSString class], fooArray, mutableArray, logAndStoreBlock);
    NSLog(@"mutable array is: %@",mutableArray);
    
}

@end

Output:

2012-02-17 12:06:29.003 HackTest[1468:207] alpha 2012-02-17 12:06:29.004 HackTest[1468:207] beta 2012-02-17 12:06:29.005 HackTest[1468:207] gamma 2012-02-17 12:06:29.006 HackTest[1468:207] delta 2012-02-17 12:06:29.007 HackTest[1468:207] epsilon 2012-02-17 12:06:29.007 HackTest[1468:207] mutable array is: ( alpha, beta, gamma, delta, epsilon )