[0x457]

> you'd get a robust C-FFI style implementation of those data structures which has been tested a lot more than some random library that has almost no existing users or active maintenance.

What are these mystical random libraries you're talking about? There is a solid C implementation of every data structure on this planet.

[simonw]

Show me a better C library for HyperLogLog than the one baked into Redis.

I went looking and the pure C ones all appeared to be untouched in 10+ years - https://github.com/ivitjuk/libhll and https://github.com/avz/hll for example.