Show HN: HyperLogLog in Zig(github.com)

            const Self = @This();
            pub fn init() Self {
                var s = Self{};
                for (s.dense) |*x| x.* = 0;
                return s;
            }
        }
    }```

    - uniqExact - the same as COUNT(DISTINCT ...) - the exact version, using a hash table;
    - uniqCombined - a combination of a linear array of small size in memory arena, a hash table, and a HyperLogLog - this data structure is similar to HyperLogLog++; the log2 of the number of cells is controllable by the user;
    - uniq - a cardinality estimator based on adaptive sampling by hash, lower quality to memory usage compared to HyperLogLog, but beats it in CPU efficiency;
    - uniqTheta - uses the Theta sketch algorithm, whatever it means;
    - uniqUpTo(N) - my favorite, uses a linear array to give the precise answer up to N, and always answers N + 1 when the number of distinct elements is larger than N;
    - groupBitmap - an exact calculation using Roaring Bitmaps, makes sense for dense integer sets;

    SELECT URL, COUNT(DISTINCT UserID) FROM pageviews GROUP BY URL