anchor.diff:                        '(simple-array (unsigned-byte 26) (4))))))
       (aref (the (simple-array (unsigned-byte 26) (4)) vec) extra-bytes)))
   
  +(declaim (inline legal-utf8-cstring))
   (defun legal-utf8-cstring (ptr start len)
     (declare (type cstr-offset start len)
              (optimize (speed 3) (safety 0) (debug 0)))
  
positive.code: (deftype cstr-offset ()
    `(integer 0 ,(1+ +cstring-path-max+)))
  
  (defun utf8-extra-bytes (code)
    (declare (type (unsigned-byte 8) code)
             (optimize (speed 3) (safety 0) (debug 0)))
  
negative.code:   (defconstant +cstring-path-max+ 65535))
  
  (defun sstring-to-cstring (sstring c-ptr)
    (declare (optimize (speed 3) (safety 0) (debug 0)))
    (let ((index 0))
      (flet ((output-octet (octet)
               (setf (cffi:mem-aref c-ptr :unsigned-char index) octet)
  