crc.d

immutable(uint[256]) crc32_lookup_table =
    {
        uint[] table;
        foreach (ref i; 0 .. 256)
        {
            uint crc = i;
            foreach (_; 0 .. 8)
                crc = crc & 1 ? (crc >> 1) ^ 0xEDB88320 : crc >> 1;
            table ~= crc;
        }
        return table[];
    }();


pure uint crc32(T)(T[] packet) if (T.sizeof == 1)
{
    uint crc = 0xFFFFFFFF;
    foreach (ref const T element; packet)
        crc = crc32_lookup_table[(crc ^ element) & 0xFF] ^ (crc >> 8);
    return ~crc;
}