uhm, this is 16 bit long, so it can have 0..2^16, so i think this comment about 256 is wrong?

I think this buffer needs to be bigger ?

Are you sure about the & in the sizeof?

I think this here is a problem, the default value is either 0 or 1 but memset does set things bytewise.

Isnt that wrong and we should only do that if the first bit is equal to request earlier on ?

I think all default values in the iterator have to be the same as we are walking the same boolean property type, why is this check here?

Nah the size is correct. Problem with 256, is that if you use a uchar to count, you will wrap in some case without a way to detect it (So for safety I switched to ushort). Will change the comment accordingly.

I will double check that. I did make a few change along the way and it is indeed not clear this is correct.

default_value is set via !! which force a full bytewise 0 and 1 to be set.

You are right the init case is not properly handle. Need to make sure that at least there is one first run being done before returning an index.

You can request an iterator on all value being TRUE or FALSE. As the default value can also be one or the other, we need to stop walking if the default value is not the same as the requested value for the iterator.