Some CRC algorithms (when using 0xFFFF as an initial value and final XOR) have a nice property that then checking the consistency of a data block that has a CRC checksum appended, the resulting checksum value is a constant. Is there an easy way to extract this constant value from boost::crc directly? Example: We use a CRC like this: typedef boost::crc_optimal<16, 0x1021, 0xFFFF, 0xFFFF, true, true> crc_type; When sending a block of data, we append the generated CRC. The receiver side feeds the complete block incluing the CRC bytes into its generator. When the data block has no errors, the crc.checksum() is always exactly 0x0F47. Currently, I manually calculate that constant by something like this: crc_type crc; crc_type::value_type val(0); crc.process_bytes(&val, sizeof(val)); m_key = crc.checksum(); Is there an easier way to extract this "crc is correct" value? Norbert