Comparer.Apply1Apply1 (F) (A) takes a type ('a, 'b, 'compare_a) F.t with two type parameters 'a, 'b and a compare type 'compare_a for 'a, and a comparer A, and creates a comparer for F.t with 'a instantiated to A.t.
module F : sig ... endinclude Ppx_compare_lib.Comparable.S1 with type 'b t := 'b tval compare :
'a Base__Ppx_compare_lib.compare ->
'a t Base__Ppx_compare_lib.compareinclude S1
with type 'b t := 'b t
with type 'compare_b compare = (A.compare, 'compare_b) F.comparetype ('a, 'compare_a) comparer := ('a, 'compare_a) tval sexp_of_compare :
('compare_a -> Sexplib0.Sexp.t) ->
'compare_a compare ->
Sexplib0.Sexp.tval compare_of_sexp :
(Sexplib0.Sexp.t -> 'compare_a) ->
Sexplib0.Sexp.t ->
'compare_a compare