extract magic constant, add [0,len] special case
extract magic constant, add [0,len] special case

LinusU/buffer,LiuDeng/buffer,beni55/buffer,LiuDeng/buffer,SAGV/buffer,btd/buffer,btd/buffer,LinusU/buffer,beni55/buffer,loon3/buffer,feross/buffer,feross/buffer,loon3/buffer,feross/buffer,SAGV/buffer