//! Different flavors of flags structures, akin to a Vec<bool>, but persistent and efficient.
//!
//! Here's a brief overview of the different flavors of flags structures:
//! - `dynamic_mmap_flags`: Base implementation of storage in mmapped files.
//! - `buffered_dynamic_flags`: Builds on top of `dynamic_mmap_flags` to provide buffered writes.
//! - `bitvec_flags`: `buffered_dynamic_flags` with in-memory bitvec for reads.
//! - `roaring_flags`: `buffered_dynamic_flags` with in-memory roaring bitmap for reads.
//! - `in_memory_bitvec_flags`: in-memory counterpart of `bitvec_flags`, bound to `UniversalRead`.
//! - `read_only_roaring_flags`: read-only counterpart of `roaring_flags`, bound to `UniversalRead`.