Module type Hashtbl.For_deriving
module type Sexp_of_m = sig ... end
module type M_of_sexp = sig ... end
val sexp_of_m__t : (module Sexp_of_m with type t = 'k) -> ('v -> Base.Sexp.t) -> ('k, 'v) t -> Base.Sexp.t
val m__t_of_sexp : (module M_of_sexp with type t = 'k) -> (Base.Sexp.t -> 'v) -> Base.Sexp.t -> ('k, 'v) t