Unnecessary Chaperones?

[default-kramer]

I mentioned on the mailing list that Typed Racket adds chaperones that seem unnecessary. I only found two examples, but if I find more I will update this item.

Example 1

Tested with 8.0.0.11--2021-03-15(c0cfd32/a) [cs]

#lang racket

(module m typed/racket
  (provide f)
  (: f (-> Any Any))
  (define (f x) x))
(require 'm)

(struct s (a b) #:transparent #:authentic)
(f (s 1 2))

Example 2

Tested with 8.0.0.11--2021-03-15(c0cfd32/a) [cs].

#lang racket

(module m typed/racket
  (provide (all-defined-out))
  (require/typed racket [prop:authentic Struct-Type-Property])
  (struct s ([a : Integer]) #:transparent
    #:property prop:authentic #t)

  (: go (-> (-> Any Any) Void))
  (define (go f)
    (println (f (s 1)))))

(require 'm)

(go identity)

I was surprised that changing the type of go to (: go (-> (-> s Any) Void)) causes the program to work, with no chaperone being generated.