probably won't happen (?)

define-struct-comment.rkt

#lang racket
(require (for-syntax racket/struct-info))
(define-values (s:p mkp recp refp setp)
  (make-struct-type 'parent #f 1 0 #f))
(define-values (s:c mkc recc refc setc)
  (make-struct-type 'child s:p 1 0 #f))
(define (refc0 c) (refc c 0))
(define-syntax P 'gotcha!)
(define-syntax C
  (make-struct-info (λ ()
                       (list #'s:c #'mkc #'recc
                             (list #'refc0 #f)
                             (list #f #f)
                             #'P))))
(struct-copy C (mkc 0 1) [mumble #:parent s:p 'blah])