Recently I have been working on benchmarks comparing techniques for calculating UTF-8 sequence lengths.The method I described in Decoding UTF-8. Part IV: Determining Sequence Length - Counting Leading Bits uses hardware-assisted counting of leading zero bits:#include <bit> int utf8_sequence_length(unsigned char lead_byte) { switch (std::countl_one(lead_byte)) { case 0: return 1; case 2: return 2; case 3: return 3; case 4: return 4; default: return 0; // invalid lead } }I was pretty disappointed ...