public unsafe ulong this[int i] { [MethodImpl(MethodImplOptions.AggressiveInlining)] get { if (i != _uint64Count - 1 || _lastUInt64ByteCount == 8) { return(BssomBinaryPrimitives.ReadUInt64LittleEndian(ref _us[i * 8])); } int startPos = (_uint64Count - 1) * 8; ulong value1 = 0; Unsafe.CopyBlock(ref Unsafe.As <ulong, byte>(ref value1), ref _us[startPos], (uint)_lastUInt64ByteCount); return(BssomBinaryPrimitives.ReadRawUInt64LittleEndian(value1)); } }