lei-hongfaan / ultimateorb.int128

Provides Int128 and UInt128.

New repo: https://github.com/LEI-Hongfaan/UltimateOrb.Core (UltimateOrb.Int128 is still an independent library/package).

ultimateorb.int128's Issues

Add PopCount functions for at least `UInt128`

I came across needing this function, and this is what I ended up with:

    public static unsafe int PopCount(UInt128 value)
    {
        var valuePtr = (ulong*)&value;
        return BitOperations.PopCount(valuePtr[0]) + BitOperations.PopCount(valuePtr[1]);
    }

UInt128.ToBigIntegerByteAray returns 17 bytes whereas Int128 only returns 16.

See here for Int128.
And here for UInt128.

I don't know if this is intentional or not because there are no code comments explaining why there is a +1 in the array allocation. But it causes problems if you switch from Int128 to UInt128 (or the other way around) and use that method to get a byte array to feed into something else (such as a hash function) because the results will be different for the same numbers which should not be the case.