Am Mi., 17. Juni 2020 um 09:33 Uhr schrieb Shiro Kawai <xxxxxx@gmail.com>:

> srfi-145 assume is allowed to do nothing.  So (maybe-ref maybe) can just be evaluated #f if maybe is Nothing?

`assume` should only do nothing in a mode that is equivalent to "-O3
-DNDEBUG=1".

(maybe-ref (nothing)) would be an error (undefined behavior) and,
unless one compiles in an unsafe mode, the underlying `assume` should
abort and show an error to the user.

> By the way, can't (assume (just? obj) message) be enough?

The idea was to use the return value of `assume`.