Implementing optimization 1, part 2
Implementing optimization 1, part 2

RoaringBitmap/RoaringBitmap,okrische/RoaringBitmap,lemire/RoaringBitmap,RoaringBitmap/RoaringBitmap,okrische/RoaringBitmap,RoaringBitmap/RoaringBitmap,RoaringBitmap/RoaringBitmap,lemire/RoaringBitmap,lemire/RoaringBitmap,lemire/RoaringBitmap,okrische/RoaringBitmap