If you don't need all the guarantees provided by std::unordered_map (pointer stability is usually the big one), you can go a /lot/ faster with a map that uses o

If you don't need all the guarantees provided by std::unordered_map (pointer stability is usually the big one), you can go a /lot/ faster with a map that uses open addressing. Some of my favorite alternative hash map implementations are ska::flat_hash_map and ska::bytell_hash_map from https://github.com/skarupke/flat_hash_map https://github.com/skarupke/flat_hash_map. They're fast, and the single header implementation makes them easy to add to a project. For my use cases they generally offer similar performance to abseil and folly F14. Don't be fooled by the fact that they haven't been updated in ~5 years. I've been using them for nearly that long and have yet to find any bugs.