Parameter Make_access.1-T
val nonempty_getter : ('at -> 'a Nonempty_getter.t) -> ('a, 'b) t -> ('at, 'bt) t
A legal implementation of this function must satisfy the following properties:
nonempty_getter Nonempty_getter.return = Fn.id
Fn.compose (nonempty_getter f) (nonempty_getter g) = nonempty_getter (fun at -> Nonempty_getter.bind (f at) ~f:g)