March 2014 update

Task/Anonymous-recursion/Objective-C/anonymous-recursion-2.m

@@ -5,21 +5,22 @@ int fib(int n) {
         @throw [NSException exceptionWithName:NSInvalidArgumentException
                                  reason:@"fib: no negative numbers"
                                userInfo:nil];
-    __block int (^f)(int);
-    f = ^(int n) {
+    int (^f)(int);
+    __block __weak int (^weak_f)(int); // block cannot capture strong reference to itself
+    weak_f = f = ^(int n) {
         if (n < 2)
             return 1;
         else
-            return f(n-1) + f(n-2);
+            return weak_f(n-1) + weak_f(n-2);
     };
     return f(n);
 }
 
 int main (int argc, const char *argv[]) {
-  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+  @autoreleasepool {
 
-  NSLog(@"%d", fib(8));
+    NSLog(@"%d", fib(8));
 
-  [pool release];
+  }
   return 0;
 }