Robin Hood tables are a common-ish hash map implementation that often shows up on benchmarks for fast inserts. Depending on the implementation, a Robin Hood tab

Robin Hood tables are a common-ish hash map implementation that often shows up on benchmarks for fast inserts. Depending on the implementation, a Robin Hood table is also a sorted sparse array! This could be useful for data that needs random access and sequential access to a subset of the sorted data, like an order book.