filter, removing bindings depending on a predicate (#165)Index.Make over arbitrary mutex and thread implementations (and remove the obligation for IO to provide this functionality). (#160, #161)merge operation, allowing concurrent read operations to share CPU resources with ongoing merges. (#152)force_merge from Index.S, due to difficulties with guaranteeing sensible semantics to this function under MRSW access patterns. (#147, #150)pwrite with len=0 (#131)log.mem on close (#135)log_async on startup (#136)First stable release.