Function indexed_bitvec_core::index_raw::select_ones

pub fn select_ones(
    index: &[u64], 
    all_bits: BitsRef, 
    target_rank: u64
) -> Option<u64>

Find the position of a set bit by its rank using the index (O(log n)).

Returns None if no suitable bit is found. It is always the case otherwise that rank_ones(index, result) == Some(target_rank) and get(result) == Some(true).