Builder that allows to concurrently build elias-fano.
The set method can be called by multiple threads.
Once the build is finished this struct can be converted to an EliasFano struct
by calling the build method which compute and store the indexes needed for
the constant time select (high-bits).
Structure with index inspired by Vigna’s simple select
This structure is efficient for DENSE bitvectors
An iterator over the simple select ones
that can be itered in both directions and has a known length
Memory usage in bytes by the variuos fields of Simple Select