// *** before: ***
// the pool was an ordinary object, and it had to be drained by hand -
// including on every early exit from the loop
int main(int argc, char *argv[]) {
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    int result = UIApplicationMain(argc, argv, nil, nil);
    [pool release];
    return result;
}

- (void)processFiles:(NSArray *)paths {
    for (NSString *path in paths) {
        NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
        NSString *text = [NSString stringWithContentsOfFile:path];
        [self handle:text];
        [pool drain];          // a break above this line leaked the pool
    }
}

// *** in version 2011: ***
// @autoreleasepool is a language construct: the pool is drained on any way
// out of the braces - return, break, or an exception
int main(int argc, char *argv[]) {
    @autoreleasepool {
        return UIApplicationMain(argc, argv, nil, nil);
    }
}

- (void)processFiles:(NSArray *)paths {
    for (NSString *path in paths) {
        @autoreleasepool {                 // memory is released every step
            NSString *text = [NSString stringWithContentsOfFile:path
                                                       encoding:NSUTF8StringEncoding
                                                          error:nil];
            [self handle:text];
            if (text.length == 0) break;   // the pool is drained anyway
        }
    }
}

// it is faster than NSAutoreleasePool as well: the runtime keeps the pool
// on a stack instead of allocating an object