Yea.Compression.BitArrayCompress.InternalSet C# (CSharp) Method

        private void InternalSet(int index, bool val)
        {
            IsDirty = true;
            int pointer = index >> 5;
            uint mask = (uint) 1 << (31 - // high order bit set
                                     (index%32));

            if (val)
                _uncompressed[pointer] |= mask;
            else
                _uncompressed[pointer] &= ~mask;
        }