Advance past 0 or more consecutive Unicode code points at the beginning of the specified string, until either the specified numCodePoints bytes have been traversed or the terminating null byte is encountered (whichever occurs first), and return the number of Unicode code points traversed. Set the specified *result to the address of the byte immediately following the last code point traversed, or to string if string is empty or numCodePoints is 0. string is necessarily null-terminated, so it cannot contain embedded null bytes. The behavior is undefined unless string contains valid UTF-8 and 0 <= numCodePoints. Note that the value returned will be in the range [0 .. numCodePoints]. Also note that string may contain less than bsl::strlen(string) Unicode code points.