robin-map

The robin-map library is a C++ implementation of a fast hash map and hash set using open-addressing and linear robin hood hashing with backward shift deletion to resolve collisions. Four classes are provided: tsl::robin_map, tsl::robin_set, tsl::robin_pg_map and tsl::robin_pg_set. The first two are faster and use a power of two growth policy, the last two use a prime growth policy instead and are able to cope better with a poor hash function. Use the prime version if there is a chance of repeating patterns in the lower bits of your hash (e.g. you are storing pointers with an identity hash function). See GrowthPolicy for details. A benchmark of tsl::robin_map against other hash maps may be found here. This page also gives some advices on which hash table structure you should try for your use case (useful if you are a bit lost with the multiple hash tables implementations in the tsl namespace).