Blocks are copied often

gistfile1.m

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{

    @autoreleasepool {
        __block int x;
            
        NSLog(@"Address of x outside of block: %p", &x);
    
        ^{
            NSLog(@"Address of x in non-assigned block: %p", &x);
        }();
        
        void (^b)(void) = ^{
            NSLog(@"Address of x in assigned block: %p", &x);
        };
        
        b();

    }
    return 0;
}

output

2012-02-02 17:23:19.010 blockcopying[39728:707] Address of x outside of block:      0x7fff5fbff918
2012-02-02 17:23:19.012 blockcopying[39728:707] Address of x in non-assigned block: 0x7fff5fbff918
2012-02-02 17:23:19.013 blockcopying[39728:707] Address of x in assigned block:     0x103000048