Recursive Block Retain Cycles

Question

Will this lead to any sort of retain cycle? Is it safe to use?

__block void (^myBlock)(int) = [^void (int i)
{
    if (i == 0)
        return;

    NSLog(@\"         


        

Answer 1

There's a simple solution that avoids the cycle and the potential need to prematurely copy:

void (^myBlock)(id,int) = ^(id thisblock, int i) {
    if (i == 0)
      return;

    NSLog(@"%d", i);
    void(^block)(id,int) = thisblock;
    block(thisblock, i - 1);
  };

myBlock(myBlock, 10);

You can add a wrapper to get the original type signature back:

void (^myBlockWrapper)(int) = ^(int i){ return myBlock(myBlock,i); }

myBlockWrapper(10);

This becomes tedious if you want to extend it to do mutual recursion, but I can't think of a good reason to do this in the first place (wouldn't a class be clearer?).