diff --git a/CHANGELOG.md b/CHANGELOG.md
index 905347d6f..ee7fe8873 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,11 @@
 # Changelog
 
 ## main
+- breaking: CCListLabel.compare and CCListLabel.equal takes the function on the elements as named arguments
+- breaking: CCListLabel.init now takes the length as a named arguments to follow the Stdlib
+- breaking: invert the argument of CCFun.compose to align it with the Stdlib
+- breaking: change the semantic of CCFloat.{min,max} with respect to NaN to follow the Stdlib
+- breaking: change the semantic of CCInt.rem with respect to negative number to follow the Stdlib
 
 ## 3.15
 
@@ -38,6 +43,7 @@
 
 ## 3.13
 
+- breaking: bump minimum version of OCaml to 4.08
 - breaking: delete containers-thread (which was deprecated)
 - breaking: pp: modify `Ext.t` so it takes surrounding value
 - breaking: remove CCShims
diff --git a/src/core/CCArray.ml b/src/core/CCArray.ml
index 00c57142d..85d498fd0 100644
--- a/src/core/CCArray.ml
+++ b/src/core/CCArray.ml
@@ -455,15 +455,6 @@ let pp_i ?(pp_start = fun _ () -> ()) ?(pp_stop = fun _ () -> ())
 let to_string ?(sep = ", ") item_to_string a =
   Array.to_list a |> List.map item_to_string |> String.concat sep
 
-let to_seq a =
-  let rec aux i () =
-    if i >= length a then
-      Seq.Nil
-    else
-      Seq.Cons (a.(i), aux (i + 1))
-  in
-  aux 0
-
 let to_iter a k = iter k a
 
 let to_gen a =
diff --git a/src/core/CCArray.mli b/src/core/CCArray.mli
index d19d42523..8d9c14e52 100644
--- a/src/core/CCArray.mli
+++ b/src/core/CCArray.mli
@@ -240,14 +240,6 @@ val to_iter : 'a t -> 'a iter
     in modification of the iterator.
     @since 2.8 *)
 
-val to_seq : 'a t -> 'a Seq.t
-(** [to_seq a] returns a [Seq.t] of the elements of an array [a].
-    The input array [a] is shared with the sequence and modification of it will result
-    in modification of the sequence.
-    Renamed from [to_std_seq] since 3.0.
-    @since 3.0
-*)
-
 val to_gen : 'a t -> 'a gen
 (** [to_gen a] returns a [gen] of the elements of an array [a]. *)
 
diff --git a/src/core/CCArrayLabels.mli b/src/core/CCArrayLabels.mli
index 8663c7ddd..2a1f705f6 100644
--- a/src/core/CCArrayLabels.mli
+++ b/src/core/CCArrayLabels.mli
@@ -219,13 +219,6 @@ val fold2 : f:('acc -> 'a -> 'b -> 'acc) -> init:'acc -> 'a t -> 'b t -> 'acc
     @raise Invalid_argument if [a] and [b] have distinct lengths.
     @since 0.20 *)
 
-val iter2 : f:('a -> 'b -> unit) -> 'a t -> 'b t -> unit
-(** [iter2 ~f a b] iterates on the two arrays [a] and [b] stepwise.
-    It is equivalent to  [f a0 b0; …; f a.(length a - 1) b.(length b - 1); ()].
-
-    @raise Invalid_argument if [a] and [b] have distinct lengths.
-    @since 0.20 *)
-
 val shuffle : 'a t -> unit
 (** [shuffle a] randomly shuffles the array [a], in place. *)
 
@@ -248,14 +241,6 @@ val to_iter : 'a t -> 'a iter
     in modification of the iterator.
     @since 2.8 *)
 
-val to_seq : 'a t -> 'a Seq.t
-(** [to_seq a] returns a [Seq.t] of the elements of an array [a].
-    The input array [a] is shared with the sequence and modification of it will result
-    in modification of the sequence.
-    Renamed from [to_std_seq] since 3.0.
-    @since 3.0
-*)
-
 val to_gen : 'a t -> 'a gen
 (** [to_gen a] returns a [gen] of the elements of an array [a]. *)
 
@@ -286,14 +271,6 @@ val pp_i :
     By defaults [pp_start] and [pp_stop] does nothing and [pp_sep] defaults to
     (fun out -> Format.fprintf out ",@ "). *)
 
-val map2 : f:('a -> 'b -> 'c) -> 'a t -> 'b t -> 'c t
-(** [map2 ~f a b] applies function [f] to all elements of [a] and [b],
-    and builds an array with the results returned by [f]:
-    [[| f a.(0) b.(0); …; f a.(length a - 1) b.(length b - 1)|]].
-
-    @raise Invalid_argument if [a] and [b] have distinct lengths.
-    @since 0.20 *)
-
 val rev : 'a t -> 'a t
 (** [rev a] copies the array [a] and reverses it in place.
     @since 0.20 *)
@@ -308,7 +285,7 @@ val filter_map : f:('a -> 'b option) -> 'a t -> 'b t
     element of [a] is discarded. *)
 
 val monoid_product : f:('a -> 'b -> 'c) -> 'a t -> 'b t -> 'c t
-(** [monoid_product ~f a b] passes all combinaisons of tuples from the two arrays [a] and [b] 
+(** [monoid_product ~f a b] passes all combinaisons of tuples from the two arrays [a] and [b]
     to the function [f].
     @since 2.8 *)
 
diff --git a/src/core/CCBool.ml b/src/core/CCBool.ml
index b7e97bb55..ab35f3626 100644
--- a/src/core/CCBool.ml
+++ b/src/core/CCBool.ml
@@ -1,9 +1,6 @@
 (* This file is free software, part of containers. See file "license" for more details. *)
 
-type t = bool
-
-let equal (a : bool) b = Stdlib.( = ) a b
-let compare (a : bool) b = Stdlib.compare a b
+include Bool
 
 let if_then f x =
   if x then
@@ -17,12 +14,6 @@ let if_then_else f g x =
   else
     g ()
 
-let to_int (x : bool) : int =
-  if x then
-    1
-  else
-    0
-
 let of_int x : t = x <> 0
 
 type 'a printer = Format.formatter -> 'a -> unit
diff --git a/src/core/CCBool.mli b/src/core/CCBool.mli
index 0ac4c40c0..81a7c3462 100644
--- a/src/core/CCBool.mli
+++ b/src/core/CCBool.mli
@@ -2,13 +2,8 @@
 
 (** Basic Bool functions *)
 
-type t = bool
-
-val compare : t -> t -> int
-(** [compare b1 b2] is the total ordering on booleans [b1] and [b2], similar to {!Stdlib.compare}. *)
-
-val equal : t -> t -> bool
-(** [equal b1 b2] is [true] if [b1] and [b2] are the same. *)
+include module type of Bool
+(** @inline *)
 
 val if_then : (unit -> 'a) -> t -> 'a option
 (** [if_then f x] is [Some (f ())] if [x] is true and None otherwise.
@@ -18,10 +13,6 @@ val if_then_else : (unit -> 'a) -> (unit -> 'a) -> t -> 'a
 (** [if_then_else f g x] is [f ()] if [x] is true and [g ()] otherwise.
     @since 3.13 *)
 
-val to_int : t -> int
-(** [to_int true = 1], [to_int false = 0].
-    @since 2.7 *)
-
 val of_int : int -> t
 (** [of_int i] is the same as [i <> 0]
     @since 2.7 *)
diff --git a/src/core/CCChar.mli b/src/core/CCChar.mli
index d18eb48ed..06a80c3da 100644
--- a/src/core/CCChar.mli
+++ b/src/core/CCChar.mli
@@ -9,12 +9,6 @@ include module type of struct
   include Char
 end
 
-val compare : t -> t -> int
-(** The comparison function for characters, with the same specification as
-    {!Stdlib.compare}.  Along with the type [t], this function [compare]
-    allows the module [Char] to be passed as argument to the functors
-    {!Set.Make} and {!Map.Make}. *)
-
 val of_int_exn : int -> t
 (** Alias to {!Char.chr}.
     Return the character with the given ASCII code.
diff --git a/src/core/CCEither.ml b/src/core/CCEither.ml
index 30a64f6ff..10832602a 100644
--- a/src/core/CCEither.ml
+++ b/src/core/CCEither.ml
@@ -5,6 +5,12 @@ type 'a equal = 'a -> 'a -> bool
 type 'a ord = 'a -> 'a -> int
 type 'a printer = Format.formatter -> 'a -> unit
 
+[@@@ifge 4.12]
+
+include Either
+
+[@@@else_]
+
 (** {2 Basics} *)
 
 type ('a, 'b) t = ('a, 'b) Either.t =
@@ -62,6 +68,8 @@ let compare ~left ~right e1 e2 =
   | Left l1, Left l2 -> left l1 l2
   | Right r1, Right r2 -> right r1 r2
 
+[@@@endif]
+
 (** {2 IO} *)
 
 let pp ~left ~right fmt = function
diff --git a/src/core/CCEither.mli b/src/core/CCEither.mli
index ce6f4e18d..31817b295 100644
--- a/src/core/CCEither.mli
+++ b/src/core/CCEither.mli
@@ -13,6 +13,13 @@ type 'a equal = 'a -> 'a -> bool
 type 'a ord = 'a -> 'a -> int
 type 'a printer = Format.formatter -> 'a -> unit
 
+[@@@ifge 4.12]
+
+include module type of Either
+(** @inline *)
+
+[@@@else_]
+
 (** {2 Basics} *)
 
 type ('a, 'b) t = ('a, 'b) Either.t =
@@ -70,6 +77,8 @@ val compare :
   ('a, 'b) t ->
   int
 
+[@@@endif]
+
 (** {2 IO} *)
 
 val pp : left:'a printer -> right:'b printer -> ('a, 'b) t printer
diff --git a/src/core/CCFloat.ml b/src/core/CCFloat.ml
index 7b62f8329..72c241bbe 100644
--- a/src/core/CCFloat.ml
+++ b/src/core/CCFloat.ml
@@ -1,13 +1,6 @@
 (* This file is free software, part of containers. See file "license" for more details. *)
 
-type t = float
-
-type fpclass = Stdlib.fpclass =
-  | FP_normal
-  | FP_subnormal
-  | FP_zero
-  | FP_infinite
-  | FP_nan
+include Float
 
 module Infix = struct
   let ( = ) : t -> t -> bool = Stdlib.( = )
@@ -27,47 +20,11 @@ include Infix
 
 [@@@ocaml.warning "-32"]
 
-let nan = Stdlib.nan
-let infinity = Stdlib.infinity
-let neg_infinity = Stdlib.neg_infinity
 let max_value = infinity
 let min_value = neg_infinity
 let max_finite_value = Stdlib.max_float
-let epsilon = Stdlib.epsilon_float
-let pi = 0x1.921fb54442d18p+1
-let is_nan x = Stdlib.(classify_float x = Stdlib.FP_nan)
-let add = ( +. )
-let sub = ( -. )
-let mul = ( *. )
-let div = ( /. )
-let neg = ( ~-. )
-let abs = Stdlib.abs_float
 let scale = ( *. )
 
-let min (x : t) y =
-  match Stdlib.classify_float x, Stdlib.classify_float y with
-  | FP_nan, _ -> y
-  | _, FP_nan -> x
-  | _ ->
-    if x < y then
-      x
-    else
-      y
-
-let max (x : t) y =
-  match Stdlib.classify_float x, Stdlib.classify_float y with
-  | FP_nan, _ -> y
-  | _, FP_nan -> x
-  | _ ->
-    if x > y then
-      x
-    else
-      y
-
-let equal (a : float) b = a = b
-let hash : t -> int = Hashtbl.hash
-let compare (a : float) b = Stdlib.compare a b
-
 [@@@ocaml.warning "+32"]
 
 type 'a printer = Format.formatter -> 'a -> unit
@@ -91,22 +48,7 @@ let sign_exn (a : float) =
   else
     compare a 0.
 
-let round x =
-  let low = floor x in
-  let high = ceil x in
-  if x -. low > high -. x then
-    high
-  else
-    low
-
-let to_int (a : float) = Stdlib.int_of_float a
-let of_int (a : int) = Stdlib.float_of_int a
-let to_string (a : float) = Stdlib.string_of_float a
 let of_string_exn (a : string) = Stdlib.float_of_string a
-
-let of_string_opt (a : string) =
-  try Some (Stdlib.float_of_string a) with Failure _ -> None
-
 let random n st = Random.State.float st n
 let random_small = random 100.0
 let random_range i j st = i +. random (j -. i) st
diff --git a/src/core/CCFloat.mli b/src/core/CCFloat.mli
index 527091948..ee97e6d3f 100644
--- a/src/core/CCFloat.mli
+++ b/src/core/CCFloat.mli
@@ -3,17 +3,8 @@
 (** Basic operations on floating-point numbers
     @since 0.6.1 *)
 
-type t = float
-
-type fpclass = Stdlib.fpclass =
-  | FP_normal
-  | FP_subnormal
-  | FP_zero
-  | FP_infinite
-  | FP_nan
-
-val nan : t
-(** [nan] is Not a Number (NaN). Equal to {!Stdlib.nan}. *)
+include module type of Float
+(** @inline *)
 
 val max_value : t
 (** [max_value] is Positive infinity. Equal to {!Stdlib.infinity}. *)
@@ -24,50 +15,13 @@ val min_value : t
 val max_finite_value : t
 (** [max_finite_value] is the largest finite float value. Equal to {!Stdlib.max_float}. *)
 
-val epsilon : t
-(** [epsilon] is the smallest positive float x such that [1.0 +. x <> 1.0].
-    Equal to {!Stdlib.epsilon_float}. *)
-
-val pi : t
-(** [pi] is the constant pi. The ratio of a circumference to its diameter.
-    @since 3.0 *)
-
-val is_nan : t -> bool
-(** [is_nan f] returns [true] if f is NaN, [false] otherwise. *)
-
-val add : t -> t -> t
-(** [add x y] is equal to [x +. y]. *)
-
-val sub : t -> t -> t
-(** [sub x y] is equal to [x -. y]. *)
-
-val neg : t -> t
-(** [neg x] is equal to [~-. x]. *)
-
-val abs : t -> t
-(** [abs x] is the absolute value of the floating-point number [x].
-    Equal to {!Stdlib.abs_float}. *)
-
 val scale : t -> t -> t
 (** [scale x y] is equal to [x *. y]. *)
 
-val min : t -> t -> t
-(** [min x y] returns the min of the two given values [x] and [y]. *)
-
-val max : t -> t -> t
-(** [max x y] returns the max of the two given values [x] and [y]. *)
-
-val equal : t -> t -> bool
-(** [equal x y] is [true] if [x] and [y] are the same. *)
-
-val compare : t -> t -> int
-(** [compare x y] is {!Stdlib.compare x y}. *)
-
 type 'a printer = Format.formatter -> 'a -> unit
 type 'a random_gen = Random.State.t -> 'a
 
 val pp : t printer
-val hash : t -> int
 val random : t -> t random_gen
 val random_small : t random_gen
 val random_range : t -> t -> t random_gen
@@ -76,11 +30,6 @@ val fsign : t -> t
 (** [fsign x] is one of [-1., -0., +0., +1.], or [nan] if [x] is NaN.
     @since 0.7 *)
 
-val round : t -> t
-(** [round x] returns the closest integer value, either above or below.
-    For [n + 0.5], [round] returns [n].
-    @since 0.20 *)
-
 exception TrapNaN of string
 
 val sign_exn : t -> int
@@ -89,23 +38,11 @@ val sign_exn : t -> int
     Note that infinities have defined signs in OCaml.
     @since 0.7 *)
 
-val to_int : t -> int
-(** Alias to {!int_of_float}.
-    Unspecified if outside of the range of integers. *)
-
-val of_int : int -> t
-(** Alias to {!float_of_int}. *)
-
-val to_string : t -> string
-
 val of_string_exn : string -> t
 (** Alias to {!float_of_string}.
     @raise Failure in case of failure.
     @since 1.2 *)
 
-val of_string_opt : string -> t option
-(** @since 3.0 *)
-
 val equal_precision : epsilon:t -> t -> t -> bool
 (** Equality with allowed error up to a non negative epsilon value. *)
 
diff --git a/src/core/CCFormat.ml b/src/core/CCFormat.ml
index ef1c9ca12..9dd8037c7 100644
--- a/src/core/CCFormat.ml
+++ b/src/core/CCFormat.ml
@@ -31,6 +31,9 @@ let break fmt (m, n) = Format.pp_print_break fmt m n
 let newline = Format.pp_force_newline
 let substring out (s, i, len) : unit = string out (String.sub s i len)
 let text = Format.pp_print_text
+let option = Format.pp_print_option
+let opt = option
+let result = Format.pp_print_result
 
 let string_lines out (s : string) : unit =
   fprintf out "@[<v>";
@@ -88,11 +91,6 @@ let iter ?(sep = return ",@ ") pp fmt seq =
         sep fmt ();
       pp fmt x)
 
-let opt pp fmt x =
-  match x with
-  | None -> Format.pp_print_string fmt "none"
-  | Some x -> Format.fprintf fmt "some %a" pp x
-
 let pair ?(sep = return ",@ ") ppa ppb fmt (a, b) =
   Format.fprintf fmt "%a%a%a" ppa a sep () ppb b
 
diff --git a/src/core/CCFormat.mli b/src/core/CCFormat.mli
index 4426f662c..12b1ca815 100644
--- a/src/core/CCFormat.mli
+++ b/src/core/CCFormat.mli
@@ -99,10 +99,16 @@ val arrayi : ?sep:unit printer -> (int * 'a) printer -> 'a array printer
 val seq : ?sep:unit printer -> 'a printer -> 'a Seq.t printer
 val iter : ?sep:unit printer -> 'a printer -> 'a iter printer
 
-val opt : 'a printer -> 'a option printer
-(** [opt pp] prints options as follows:
-    - [Some x] will become "some foo" if [pp x ---> "foo"].
-    - [None] will become "none". *)
+val option : ?none:unit printer -> 'a printer -> 'a option printer
+(** [opt ?none pp] prints options as follows:
+        - [Some x] will become [pp x]
+        - [None] will become [none ()]
+    @since NEXT_RELEASE *)
+
+val opt : ?none:unit printer -> 'a printer -> 'a option printer
+(** Alias of {!option} *)
+
+val result : ok:'a printer -> error:'e printer -> ('a, 'e) result printer
 
 (** In the tuple printers, the [sep] argument is only available.
     @since 0.17 *)
diff --git a/src/core/CCFun.ml b/src/core/CCFun.ml
index abb2a6a26..7605d7668 100644
--- a/src/core/CCFun.ml
+++ b/src/core/CCFun.ml
@@ -10,7 +10,13 @@ include Fun
 
 let[@inline] and_pred f g x = f x && g x
 let[@inline] or_pred f g x = f x || g x
-let[@inline] compose f g x = g (f x)
+
+[@@@iflt 5.2]
+
+let[@inline] compose f g x = f (g x)
+
+[@@@endif]
+
 let[@inline] compose_binop f g x y = g (f x) (f y)
 let[@inline] curry f x y = f (x, y)
 let[@inline] uncurry f (x, y) = f x y
@@ -63,7 +69,7 @@ let rec iterate n f x =
 
 module Infix = struct
   (* default implem for some operators *)
-  let ( %> ) = compose
+  let ( %> ) f g = compose g f
   let[@inline] ( % ) f g x = f (g x)
   let ( let@ ) = ( @@ )
   let ( ||> ) (a, b) f = f a b
diff --git a/src/core/CCFun.mli b/src/core/CCFun.mli
index 882611012..d5d33c74c 100644
--- a/src/core/CCFun.mli
+++ b/src/core/CCFun.mli
@@ -17,8 +17,13 @@ val or_pred : ('a -> bool) -> ('a -> bool) -> 'a -> bool
     @since 3.13.1
 *)
 
-val compose : ('a -> 'b) -> ('b -> 'c) -> 'a -> 'c
-(** [compose f g x] is [g (f x)]. Composition. *)
+[@@@iflt 5.2]
+
+val compose : ('b -> 'c) -> ('a -> 'b) -> 'a -> 'c
+(** [compose f g x] is [f (g x)]. Composition.
+    @since NEXT_RELEASE arguments are inversted *)
+
+[@@@endif]
 
 val compose_binop : ('a -> 'b) -> ('b -> 'b -> 'c) -> 'a -> 'a -> 'c
 (** [compose_binop f g] is [fun x y -> g (f x) (f y)].
@@ -84,7 +89,8 @@ val iterate : int -> ('a -> 'a) -> 'a -> 'a
 
 module Infix : sig
   val ( %> ) : ('a -> 'b) -> ('b -> 'c) -> 'a -> 'c
-  (** [(f %> g) x] or [(%>) f g x] is [g (f x)]. Alias to [compose]. *)
+  (** [(f %> g) x] or [(%>) f g x] is [g (f x)]. Infix version of [compose].
+      The order of the arguments of [%>] and {!compose} are inverted. *)
 
   val ( % ) : ('b -> 'c) -> ('a -> 'b) -> 'a -> 'c
   (** [(f % g) x] or [(%) f g x] is [f (g x)]. Mathematical composition. *)
diff --git a/src/core/CCHashtbl.ml b/src/core/CCHashtbl.ml
index 9406cbe30..6356d15eb 100644
--- a/src/core/CCHashtbl.ml
+++ b/src/core/CCHashtbl.ml
@@ -189,11 +189,6 @@ module type S = sig
       using [f] in an unspecified order.
       @since 3.3 *)
 
-  val add_seq : 'a t -> (key * 'a) Seq.t -> unit
-  (** Add the corresponding pairs to the table, using {!Hashtbl.add}.
-      Renamed from [add_std_seq] since 3.0.
-      @since 3.0 *)
-
   val add_seq_with :
     f:(key -> 'a -> 'a -> 'a) -> 'a t -> (key * 'a) Seq.t -> unit
   (** Add the corresponding pairs to the table, using {!Hashtbl.add}.
@@ -211,11 +206,6 @@ module type S = sig
       using [f] in an unspecified order.
       @since 3.3 *)
 
-  val of_seq : (key * 'a) Seq.t -> 'a t
-  (** From the given bindings, added in order.
-      Renamed from [of_std_seq] since 3.0.
-      @since 3.0 *)
-
   val of_seq_with : f:(key -> 'a -> 'a -> 'a) -> (key * 'a) Seq.t -> 'a t
   (** From the given bindings, added in order.
       If a key occurs multiple times in the input, the values are combined
@@ -349,8 +339,6 @@ module Make (X : Hashtbl.HashedType) :
         | exception Not_found -> add tbl k v
         | v2 -> replace tbl k (f k v v2))
 
-  let add_seq tbl seq = Seq.iter (fun (k, v) -> add tbl k v) seq
-
   let add_seq_with ~f tbl seq =
     Seq.iter
       (fun (k, v) ->
@@ -366,7 +354,6 @@ module Make (X : Hashtbl.HashedType) :
     tbl
 
   let of_iter i = mk_tbl_ add_iter i
-  let of_seq i = mk_tbl_ add_seq i
   let of_iter_with ~f i = mk_tbl_ (add_iter_with ~f) i
   let of_seq_with ~f i = mk_tbl_ (add_seq_with ~f) i
   let add_iter_count tbl i = i (fun k -> incr tbl k)
diff --git a/src/core/CCHashtbl.mli b/src/core/CCHashtbl.mli
index d01de1340..c5445a677 100644
--- a/src/core/CCHashtbl.mli
+++ b/src/core/CCHashtbl.mli
@@ -253,11 +253,6 @@ module type S = sig
       using [f] in an unspecified order.
       @since 3.3 *)
 
-  val add_seq : 'a t -> (key * 'a) Seq.t -> unit
-  (** Add the corresponding pairs to the table, using {!Hashtbl.add}.
-      Renamed from [add_std_seq] since 3.0.
-      @since 3.0 *)
-
   val add_seq_with :
     f:(key -> 'a -> 'a -> 'a) -> 'a t -> (key * 'a) Seq.t -> unit
   (** Add the corresponding pairs to the table, using {!Hashtbl.add}.
@@ -275,11 +270,6 @@ module type S = sig
       using [f] in an unspecified order.
       @since 3.3 *)
 
-  val of_seq : (key * 'a) Seq.t -> 'a t
-  (** From the given bindings, added in order.
-      Renamed from [of_std_seq] since 3.0.
-      @since 3.0 *)
-
   val of_seq_with : f:(key -> 'a -> 'a -> 'a) -> (key * 'a) Seq.t -> 'a t
   (** From the given bindings, added in order.
       If a key occurs multiple times in the input, the values are combined
diff --git a/src/core/CCInt.ml b/src/core/CCInt.ml
index a2efe7bc6..801b08578 100644
--- a/src/core/CCInt.ml
+++ b/src/core/CCInt.ml
@@ -2,24 +2,8 @@
 
 include Int
 
-type t = int
 type 'a iter = ('a -> unit) -> unit
 
-let zero = 0
-let one = 1
-let minus_one = -1
-let add = ( + )
-let sub = ( - )
-let mul = ( * )
-let div = ( / )
-let succ = succ
-let pred = pred
-let abs = abs
-let max_int = max_int
-let min_int = min_int
-let equal (a : int) b = Stdlib.( = ) a b
-let compare (a : int) b = compare a b
-
 (* use FNV:
    https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function *)
 let hash (n : int) : int =
@@ -65,7 +49,6 @@ let range' i j yield =
     range i (j + 1) yield
 
 let sign i = compare i 0
-let neg i = -i
 
 let pow a b =
   let rec aux acc = function
@@ -119,9 +102,13 @@ end
 
 include Infix
 
+[@@@iflt 4.13]
+
 let min : t -> t -> t = Stdlib.min
 let max : t -> t -> t = Stdlib.max
 
+[@@@endif]
+
 let floor_div a n =
   if a < 0 && n >= 0 then
     ((a + 1) / n) - 1
@@ -147,11 +134,8 @@ let random_small = random 100
 let random_range i j st = i + random (j - i) st
 let pp fmt = Format.pp_print_int fmt
 let most_significant_bit = -1 lxor (-1 lsr 1)
-let to_string = string_of_int
 let of_string s = try Some (int_of_string s) with Failure _ -> None
 let of_string_exn = Stdlib.int_of_string
-let to_float = float_of_int
-let of_float = int_of_float
 
 type output = char -> unit
 
@@ -248,11 +232,3 @@ let popcount (b : int) : int =
   let b = add b (shift_right_logical b 32) in
   let b = logand b 0x7fL in
   to_int b
-
-let logand = ( land )
-let logor = ( lor )
-let logxor = ( lxor )
-let lognot = lnot
-let shift_left = ( lsl )
-let shift_right = ( asr )
-let shift_right_logical = ( lsr )
diff --git a/src/core/CCInt.mli b/src/core/CCInt.mli
index 65b01ef18..525d8bf00 100644
--- a/src/core/CCInt.mli
+++ b/src/core/CCInt.mli
@@ -5,65 +5,6 @@
 include module type of Int
 (** @inline *)
 
-type t = int
-
-val zero : t
-(** [zero] is the integer [0].
-    @since 3.0 *)
-
-val one : t
-(** [one] is the integer [1].
-    @since 3.0 *)
-
-val minus_one : t
-(** [minus_one] is the integer [-1].
-    @since 3.0 *)
-
-val add : t -> t -> t
-(** [add x y] is [x + y].
-    @since 3.0 *)
-
-val sub : t -> t -> t
-(** [sub x y] is [x - y].
-    @since 3.0 *)
-
-val mul : t -> t -> t
-(** [mul x y] is [x * y].
-    @since 3.0 *)
-
-val div : t -> t -> t
-(** [div x y] is [x / y]
-    @since 3.0 *)
-
-val succ : t -> t
-(** [succ x] is [x + 1].
-    @since 3.0 *)
-
-val pred : t -> t
-(** [pred x] is [x - 1].
-    @since 3.0 *)
-
-val abs : t -> t
-(** [abs x] is the absolute value of [x]. It is [x] if [x] is positive
-    and [neg x] otherwise.
-    @since 3.0 *)
-
-val max_int : t
-(** [max_int] is the maximum integer.
-    @since 3.0 *)
-
-val min_int : t
-(** [min_int] is the minimum integer.
-    @since 3.0 *)
-
-val compare : t -> t -> int
-(** [compare x y] is the comparison function for integers
-    with the same specification as {!Stdlib.compare}. *)
-
-val equal : t -> t -> bool
-(** [equal x y] is [true] iff [x] and [y] are equal.
-    Equality function for integers. *)
-
 val hash : t -> int
 (** [hash x] computes the hash of [x]. *)
 
@@ -71,11 +12,6 @@ val sign : t -> int
 (** [sign x] return [0] if [x = 0], [-1] if [x < 0] and [1] if [x > 0].
     Same as [compare x 0].*)
 
-val neg : t -> t
-(** [neg x] is [- x].
-    Unary negation.
-    @since 0.5 *)
-
 val pow : t -> t -> t
 (** [pow base exponent] returns [base] raised to the power of [exponent].
     [pow x y = x^y] for positive integers [x] and [y].
@@ -103,22 +39,6 @@ val random_range : int -> int -> t random_gen
 val pp : t printer
 (** [pp ppf x] prints the integer [x] on [ppf]. *)
 
-val to_float : t -> float
-(** [to_float] is the same as [float_of_int]
-    @since 3.0*)
-
-[@@@ocaml.warning "-32"]
-
-val of_float : float -> t
-(** [to_float] is the same as [int_of_float]
-    @since 3.0*)
-
-[@@@ocaml.warning "+32"]
-
-val to_string : t -> string
-(** [to_string x] returns the string representation of the integer [x], in signed decimal.
-    @since 0.13 *)
-
 val of_string : string -> t option
 (** [of_string s] converts the given string [s] into an integer.
     Safe version of {!of_string_exn}.
@@ -130,11 +50,6 @@ val of_string_exn : string -> t
     @raise Failure in case of failure.
     @since 3.0 *)
 
-val of_float : float -> t
-(** [of_float x] converts the given floating-point number [x] to an integer.
-    Alias to {!int_of_float}.
-    @since 3.0 *)
-
 val pp_binary : t printer
 (** [pp_binary ppf x] prints [x] on [ppf].
     Print as "0b00101010".
@@ -144,6 +59,8 @@ val to_string_binary : t -> string
 (** [to_string_binary x] returns the string representation of the integer [x], in binary.
     @since 0.20 *)
 
+[@@@iflt 4.13]
+
 val min : t -> t -> t
 (** [min x y] returns the minimum of the two integers [x] and [y].
     @since 0.17 *)
@@ -152,6 +69,8 @@ val max : t -> t -> t
 (** [max x y] returns the maximum of the two integers [x] and [y].
     @since 0.17 *)
 
+[@@@endif]
+
 val range_by : step:t -> t -> t -> t iter
 (** [range_by ~step i j] iterates on integers from [i] to [j] included,
     where the difference between successive elements is [step].
@@ -173,34 +92,6 @@ val popcount : t -> int
 (** Number of bits set to 1
     @since 3.0 *)
 
-val logand : t -> t -> t
-(** [logand] is the same as [(land)].
-    @since 3.0 *)
-
-val logor : t -> t -> t
-(** [logand] is the same as [(lor)].
-    @since 3.0 *)
-
-val logxor : t -> t -> t
-(** [logxor] is the same as [(lxor)].
-    @since 3.0 *)
-
-val lognot : t -> t
-(** [logand] is the same as [lnot].
-    @since 3.0 *)
-
-val shift_left : t -> int -> t
-(** [shift_left] is the same as [(lsl)].
-    @since 3.0 *)
-
-val shift_right : t -> int -> t
-(** [shift_right] is the same as [(asr)].
-    @since 3.0 *)
-
-val shift_right_logical : t -> int -> t
-(** [shift_right_logical] is the same as [(lsr)].
-    @since 3.0 *)
-
 (** {2 Infix Operators}
 
     @since 0.17 *)
diff --git a/src/core/CCInt32.ml b/src/core/CCInt32.ml
index 42cbdf5cc..45b3f4a51 100644
--- a/src/core/CCInt32.ml
+++ b/src/core/CCInt32.ml
@@ -2,9 +2,18 @@
 
 include Int32
 
+[@@@iflt 4.13]
+
 let min : t -> t -> t = Stdlib.min
 let max : t -> t -> t = Stdlib.max
+
+[@@@endif]
+[@@@iflt 5.1]
+
 let hash x = Stdlib.abs (to_int x)
+
+[@@@endif]
+
 let sign i = compare i zero
 
 let pow a b =
@@ -110,7 +119,6 @@ let random_range i j st = add i (random (sub j i) st)
 
 let of_string_exn = of_string
 let of_string x = try Some (of_string_exn x) with Failure _ -> None
-let of_string_opt = of_string
 let most_significant_bit = logxor (neg 1l) (shift_right_logical (neg 1l) 1)
 
 type output = char -> unit
diff --git a/src/core/CCInt32.mli b/src/core/CCInt32.mli
index 218168d7e..bd1940cde 100644
--- a/src/core/CCInt32.mli
+++ b/src/core/CCInt32.mli
@@ -18,6 +18,8 @@ include module type of struct
   include Int32
 end
 
+[@@@iflt 4.13]
+
 val min : t -> t -> t
 (** [min x y] returns the minimum of the two integers [x] and [y].
     @since 3.0 *)
@@ -26,10 +28,15 @@ val max : t -> t -> t
 (** [max x y] returns the maximum of the two integers [x] and [y].
     @since 3.0 *)
 
+[@@@endif]
+[@@@iflt 5.1]
+
 val hash : t -> int
 (** [hash x] computes the hash of [x].
     Like {!Stdlib.abs (to_int x)}. *)
 
+[@@@endif]
+
 val sign : t -> int
 (** [sign x] return [0] if [x = 0], [-1] if [x < 0] and [1] if [x > 0].
     Same as [compare x zero].
@@ -81,9 +88,6 @@ val of_string : string -> t option
 (** [of_string s] is the safe version of {!of_string_exn}.
     Like {!of_string_exn}, but return [None] instead of raising. *)
 
-val of_string_opt : string -> t option
-(** [of_string_opt s] is an alias to {!of_string}. *)
-
 val of_string_exn : string -> t
 (** [of_string_exn s] converts the given string [s] into a 32-bit integer.
     Alias to {!Int32.of_string}.
diff --git a/src/core/CCInt64.ml b/src/core/CCInt64.ml
index 80b22e67f..8bb45ead4 100644
--- a/src/core/CCInt64.ml
+++ b/src/core/CCInt64.ml
@@ -2,8 +2,13 @@
 
 include Int64
 
+[@@@iflt 4.13]
+
 let min : t -> t -> t = Stdlib.min
 let max : t -> t -> t = Stdlib.max
+
+[@@@endif]
+
 let sign i = compare i zero
 
 (* use FNV:
@@ -126,7 +131,6 @@ let random_range i j st = add i (random (sub j i) st)
 
 let of_string_exn = of_string
 let of_string x = try Some (of_string_exn x) with Failure _ -> None
-let of_string_opt = of_string
 let most_significant_bit = logxor (neg 1L) (shift_right_logical (neg 1L) 1)
 
 type output = char -> unit
diff --git a/src/core/CCInt64.mli b/src/core/CCInt64.mli
index 3466d2899..050553289 100644
--- a/src/core/CCInt64.mli
+++ b/src/core/CCInt64.mli
@@ -18,6 +18,8 @@ include module type of struct
   include Int64
 end
 
+[@@@iflt 4.13]
+
 val min : t -> t -> t
 (** [min x y] returns the minimum of the two integers [x] and [y].
     @since 3.0 *)
@@ -26,10 +28,15 @@ val max : t -> t -> t
 (** [max x y] returns the maximum of the two integers [x] and [y].
     @since 3.0 *)
 
+[@@@endif]
+[@@@iflt 5.1]
+
 val hash : t -> int
 (** [hash x] computes the hash of [x], a non-negative integer.
     Uses FNV since 3.10 *)
 
+[@@@endif]
+
 val hash_to_int64 : t -> t
 (** Like {!hash} but does not truncate.
     Uses FNV.
@@ -86,10 +93,6 @@ val of_string : string -> t option
 (** [of_string s] is the safe version of {!of_string_exn}.
     Like {!of_string_exn}, but return [None] instead of raising. *)
 
-val of_string_opt : string -> t option
-(** [of_string_opt s] is an alias to {!of_string}.
-    @since 2.1 *)
-
 val of_string_exn : string -> t
 (** [of_string_exn s] converts the given string [s] into a 64-bit integer.
     Alias to {!Int64.of_string}.
diff --git a/src/core/CCList.ml b/src/core/CCList.ml
index 75684ce08..00747c05b 100644
--- a/src/core/CCList.ml
+++ b/src/core/CCList.ml
@@ -1,43 +1,15 @@
-(* backport new functions from stdlib here *)
-
-[@@@ocaml.warning "-32"]
-
-let rec compare_lengths l1 l2 =
-  match l1, l2 with
-  | [], [] -> 0
-  | [], _ :: _ -> -1
-  | _ :: _, [] -> 1
-  | _ :: tail1, _ :: tail2 -> compare_lengths tail1 tail2
-
-let rec compare_length_with l n =
-  match l, n with
-  | _ when n < 0 -> 1
-  | [], 0 -> 0
-  | [], _ -> -1
-  | _ :: tail, _ -> compare_length_with tail (n - 1)
-
-let rec assoc_opt x = function
-  | [] -> None
-  | (y, v) :: _ when Stdlib.( = ) x y -> Some v
-  | _ :: tail -> assoc_opt x tail
-
-let rec assq_opt x = function
-  | [] -> None
-  | (y, v) :: _ when Stdlib.( == ) x y -> Some v
-  | _ :: tail -> assq_opt x tail
-
-[@@@ocaml.warning "+32"]
-
-(* end of backport *)
-
 include List
 
 let empty = []
 
+[@@@iflt 5.1]
+
 let is_empty = function
   | [] -> true
   | _ :: _ -> false
 
+[@@@endif]
+
 let mguard c =
   if c then
     [ () ]
@@ -391,25 +363,27 @@ let[@tail_mod_cons] rec unfold f seed =
   | Some (v, next) -> v :: unfold f next
 
 [@@@endif]
+[@@@iflt 4.12]
 
-let rec compare f l1 l2 =
+let rec compare cmp l1 l2 =
   match l1, l2 with
   | [], [] -> 0
   | _, [] -> 1
   | [], _ -> -1
   | x1 :: l1', x2 :: l2' ->
-    let c = f x1 x2 in
+    let c = cmp x1 x2 in
     if c <> 0 then
       c
     else
-      compare f l1' l2'
+      compare cmp l1' l2'
 
-let rec equal f l1 l2 =
+let rec equal eq l1 l2 =
   match l1, l2 with
   | [], [] -> true
   | [], _ | _, [] -> false
-  | x1 :: l1', x2 :: l2' -> f x1 x2 && equal f l1' l2'
+  | x1 :: l1', x2 :: l2' -> eq x1 x2 && equal eq l1' l2'
 
+[@@@endif]
 [@@@iflt 5.1]
 
 let rec flat_map_kont f l kont =
@@ -969,6 +943,8 @@ let find_pred_exn p l =
   | None -> raise Not_found
   | Some x -> x
 
+[@@@iflt 5.1]
+
 let find_mapi f l =
   let rec aux f i = function
     | [] -> None
@@ -979,8 +955,13 @@ let find_mapi f l =
   in
   aux f 0 l
 
+[@@@endif]
+[@@@iflt 4.10]
+
 let find_map f l = find_mapi (fun _ -> f) l
 
+[@@@endif]
+
 let find_idx p l =
   find_mapi
     (fun i x ->
@@ -999,6 +980,8 @@ let remove ~eq x l =
   in
   remove' eq x [] l
 
+[@@@iflt 5.1]
+
 let filter_map f l =
   let rec recurse acc l =
     match l with
@@ -1013,6 +996,8 @@ let filter_map f l =
   in
   recurse [] l
 
+[@@@endif]
+
 let keep_some l = filter_map (fun x -> x) l
 
 let keep_ok l =
@@ -1215,6 +1200,9 @@ let inter ~eq l1 l2 =
   in
   inter eq [] l1 l2
 
+[@@@iflt 5.1]
+
+(* Because our map is tail rec between 4.13 and 5.1 *)
 let mapi f l =
   let r = ref 0 in
   map
@@ -1224,6 +1212,8 @@ let mapi f l =
       y)
     l
 
+[@@@endif]
+
 let iteri f l =
   let rec aux f i l =
     match l with
@@ -1547,11 +1537,6 @@ let to_string ?(start = "") ?(stop = "") ?(sep = ", ") item_to_string l =
 
 let to_iter l k = List.iter k l
 
-let rec to_seq l () =
-  match l with
-  | [] -> Seq.Nil
-  | x :: tl -> Seq.Cons (x, to_seq tl)
-
 let of_iter i =
   let l = ref [] in
   i (fun x -> l := x :: !l);
diff --git a/src/core/CCList.mli b/src/core/CCList.mli
index f1d31605c..4fcb8dec7 100644
--- a/src/core/CCList.mli
+++ b/src/core/CCList.mli
@@ -16,10 +16,14 @@ type +'a t = 'a list
 val empty : 'a t
 (** [empty] is [[]]. *)
 
+[@@@iflt 5.1]
+
 val is_empty : _ t -> bool
 (** [is_empty l] returns [true] iff [l = []].
     @since 0.11 *)
 
+[@@@endif]
+
 val cons_maybe : 'a option -> 'a t -> 'a t
 (** [cons_maybe (Some x) l] is [x :: l].
     [cons_maybe None l] is [l].
@@ -127,11 +131,6 @@ val count_true_false : ('a -> bool) -> 'a list -> int * int
     that satisfy the predicate [p], and [int2] the number of elements that do not satisfy [p].
     @since 2.4 *)
 
-val init : int -> (int -> 'a) -> 'a t
-(** [init len f] is [f 0; f 1; …; f (len-1)].
-    @raise Invalid_argument if len < 0.
-    @since 0.6 *)
-
 val combine : 'a list -> 'b list -> ('a * 'b) list
 (** [combine [a1; …; an] [b1; …; bn]] is [[(a1,b1); …; (an,bn)]].
     Transform two lists into a list of pairs.
@@ -161,25 +160,17 @@ val split : ('a * 'b) t -> 'a t * 'b t
     @since 1.2, but only
     @since 2.2 with labels *)
 
+[@@@iflt 4.12]
+
 val compare : ('a -> 'a -> int) -> 'a t -> 'a t -> int
 (** [compare cmp l1 l2] compares the two lists [l1] and [l2]
     using the given comparison function [cmp]. *)
 
-val compare_lengths : 'a t -> 'b t -> int
-(** [compare_lengths l1 l2] compare the lengths of the two lists [l1] and [l2].
-    Equivalent to [compare (length l1) (length l2)] but more efficient.
-    @since 1.5, but only
-    @since 2.2 with labels *)
-
-val compare_length_with : 'a t -> int -> int
-(** [compare_length_with l x] compares the length of the list [l] to an integer [x].
-    Equivalent to [compare (length l) x] but more efficient.
-    @since 1.5, but only
-    @since 2.2 with labels *)
-
 val equal : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool
 (** [equal p l1 l2] returns [true] if [l1] and [l2] are equal. *)
 
+[@@@endif]
+
 val flat_map : ('a -> 'b t) -> 'a t -> 'b t
 (** [flat_map f l] maps and flattens at the same time (safe). Evaluation order is not guaranteed. *)
 
@@ -437,26 +428,28 @@ val find_pred : ('a -> bool) -> 'a t -> 'a option
     or returns [None] if no element satisfies [p].
     @since 0.11 *)
 
-val find_opt : ('a -> bool) -> 'a t -> 'a option
-(** [find_opt p l] is the safe version of {!find}.
-    @since 1.5, but only
-    @since 2.2 with labels *)
-
 val find_pred_exn : ('a -> bool) -> 'a t -> 'a
 (** [find_pred_exn p l] is the unsafe version of {!find_pred}.
     @raise Not_found if no such element is found.
     @since 0.11 *)
 
+[@@@iflt 4.10]
+
 val find_map : ('a -> 'b option) -> 'a t -> 'b option
 (** [find_map f l] traverses [l], applying [f] to each element. If for
     some element [x], [f x = Some y], then [Some y] is returned. Otherwise
     the call returns [None].
     @since 0.11 *)
 
+[@@@endif]
+[@@@iflt 5.1]
+
 val find_mapi : (int -> 'a -> 'b option) -> 'a t -> 'b option
 (** [find_mapi f l] is like {!find_map}, but also pass the index to the predicate function.
     @since 0.11 *)
 
+[@@@endif]
+
 val find_idx : ('a -> bool) -> 'a t -> (int * 'a) option
 (** [find_idx p x] returns [Some (i,x)] where [x] is the [i]-th element of [l],
     and [p x] holds. Otherwise returns [None]. *)
@@ -467,11 +460,6 @@ val remove : eq:('a -> 'a -> bool) -> key:'a -> 'a t -> 'a t
     @since 0.11 *)
 (* FIXME: the original CCList.mli uses ~x instead of ~key !! *)
 
-val filter_map : ('a -> 'b option) -> 'a t -> 'b t
-(** [filter_map f l] is the sublist of [l] containing only elements for which
-    [f] returns [Some e].
-    Map and remove elements at the same time. *)
-
 val keep_some : 'a option t -> 'a t
 (** [keep_some l] retains only elements of the form [Some x].
     Like [filter_map CCFun.id].
@@ -574,16 +562,6 @@ val group_succ : eq:('a -> 'a -> bool) -> 'a list -> 'a list list
 
 (** {2 Indices} *)
 
-val mapi : (int -> 'a -> 'b) -> 'a t -> 'b t
-(** [mapi f l] is like {!map}, but the function [f] is applied to the index of
-    the element as first argument (counting from 0), and the element
-    itself as second argument. *)
-
-val iteri : (int -> 'a -> unit) -> 'a t -> unit
-(** [iteri f l] is like {!val-iter}, but the function [f] is applied to the index of
-    the element as first argument (counting from 0), and the element
-    itself as second argument. *)
-
 val iteri2 : (int -> 'a -> 'b -> unit) -> 'a t -> 'b t -> unit
 (** [iteri2 f l1 l2] applies [f] to the two lists [l1] and [l2] simultaneously.
     The integer passed to [f] indicates the index of element.
@@ -758,14 +736,6 @@ val assoc_opt : eq:('a -> 'a -> bool) -> 'a -> ('a * 'b) t -> 'b option
     @since 1.5, but only
     @since 2.0 with labels *)
 
-val assq_opt : 'a -> ('a * 'b) t -> 'b option
-(** [assq_opt k alist] returns [Some v] if the given key [k] is present into [alist].
-    Like [Assoc.assoc_opt] but use physical equality instead of structural equality
-    to compare keys.
-    Safe version of {!assq}.
-    @since 1.5, but only
-    @since 2.0 with labels *)
-
 val mem_assoc : ?eq:('a -> 'a -> bool) -> 'a -> ('a * _) t -> bool
 (** [mem_assoc ?eq k alist] returns [true] iff [k] is a key in [alist].
     Like [Assoc.mem].
@@ -884,11 +854,6 @@ val to_iter : 'a t -> 'a iter
 (** [to_iter l] returns a [iter] of the elements of the list [l].
     @since 2.8 *)
 
-val to_seq : 'a t -> 'a Seq.t
-(** [to_seq l] returns a [Seq.t] of the elements of the list [l].
-    Renamed from [to_std_seq] since 3.0.
-    @since 3.0 *)
-
 val of_iter : 'a iter -> 'a t
 (** [of_iter iter] builds a list from a given [iter].
     In the result, elements appear in the same order as they did in the source [iter].
@@ -899,12 +864,6 @@ val of_seq_rev : 'a Seq.t -> 'a t
     Renamed from [to_std_seq_rev] since 3.0.
     @since 3.0 *)
 
-val of_seq : 'a Seq.t -> 'a t
-(** [of_seq seq] builds a list from a given [Seq.t].
-    In the result, elements appear in the same order as they did in the source [Seq.t].
-    Renamed from [of_std_seq] since 3.0.
-    @since 3.0 *)
-
 val to_gen : 'a t -> 'a gen
 (** [to_gen l] returns a [gen] of the elements of the list [l]. *)
 
diff --git a/src/core/CCListLabels.mli b/src/core/CCListLabels.mli
index 83421d6c6..1f75d3fd7 100644
--- a/src/core/CCListLabels.mli
+++ b/src/core/CCListLabels.mli
@@ -18,18 +18,18 @@ type 'a t = 'a list
 val empty : 'a t
 (** [empty] is [[]]. *)
 
+[@@@iflt 5.1]
+
 val is_empty : _ t -> bool
 (** [is_empty l] returns [true] iff [l = []].
     @since 0.11 *)
 
+[@@@endif]
+
 val map : f:('a -> 'b) -> 'a t -> 'b t
 (** [map ~f [a0; a1; …; an]] applies function [f] in turn to [[a0; a1; …; an]].
     Safe version of {!List.map}. *)
 
-val cons : 'a -> 'a t -> 'a t
-(** [cons x l] is [x::l].
-    @since 0.12 *)
-
 val append : 'a t -> 'a t -> 'a t
 (** [append l1 l2] returns the list that is the concatenation of [l1] and [l2].
     Safe version of {!List.append}. *)
@@ -160,11 +160,6 @@ val count_true_false : f:('a -> bool) -> 'a list -> int * int
     that satisfy the predicate [f], and [int2] the number of elements that do not satisfy [f].
     @since 2.4 *)
 
-val init : int -> f:(int -> 'a) -> 'a t
-(** [init len ~f] is [f 0; f 1; …; f (len-1)].
-    @raise Invalid_argument if len < 0.
-    @since 0.6 *)
-
 val combine : 'a list -> 'b list -> ('a * 'b) list
 (** [combine [a1; …; an] [b1; …; bn]] is [[(a1,b1); …; (an,bn)]].
     Transform two lists into a list of pairs.
@@ -194,25 +189,17 @@ val split : ('a * 'b) t -> 'a t * 'b t
     @since 1.2, but only
     @since 2.2 with labels *)
 
-val compare : ('a -> 'a -> int) -> 'a t -> 'a t -> int
+[@@@iflt 4.12]
+
+val compare : cmp:('a -> 'a -> int) -> 'a t -> 'a t -> int
 (** [compare cmp l1 l2] compares the two lists [l1] and [l2]
     using the given comparison function [cmp]. *)
 
-val compare_lengths : 'a t -> 'b t -> int
-(** [compare_lengths l1 l2] compare the lengths of the two lists [l1] and [l2].
-    Equivalent to [compare (length l1) (length l2)] but more efficient.
-    @since 1.5, but only
-    @since 2.2 with labels *)
-
-val compare_length_with : 'a t -> int -> int
-(** [compare_length_with l x] compares the length of the list [l] to an integer [x].
-    Equivalent to [compare (length l) x] but more efficient.
-    @since 1.5, but only
-    @since 2.2 with labels *)
-
-val equal : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool
+val equal : eq:('a -> 'a -> bool) -> 'a t -> 'a t -> bool
 (** [equal p l1 l2] returns [true] if [l1] and [l2] are equal. *)
 
+[@@@endif]
+
 val flat_map : f:('a -> 'b t) -> 'a t -> 'b t
 (** [flat_map ~f l] maps and flattens at the same time (safe). Evaluation order is not guaranteed. *)
 
@@ -470,26 +457,28 @@ val find_pred : f:('a -> bool) -> 'a t -> 'a option
     or returns [None] if no element satisfies [f].
     @since 0.11 *)
 
-val find_opt : f:('a -> bool) -> 'a t -> 'a option
-(** [find_opt ~f l] is the safe version of {!find}.
-    @since 1.5, but only
-    @since 2.2 with labels *)
-
 val find_pred_exn : f:('a -> bool) -> 'a t -> 'a
 (** [find_pred_exn ~f l] is the unsafe version of {!find_pred}.
     @raise Not_found if no such element is found.
     @since 0.11 *)
 
+[@@@iflt 4.10]
+
 val find_map : f:('a -> 'b option) -> 'a t -> 'b option
 (** [find_map ~f l] traverses [l], applying [f] to each element. If for
     some element [x], [f x = Some y], then [Some y] is returned. Otherwise
     the call returns [None].
     @since 0.11 *)
 
+[@@@endif]
+[@@@iflt 5.1]
+
 val find_mapi : f:(int -> 'a -> 'b option) -> 'a t -> 'b option
 (** [find_mapi ~f l] is like {!find_map}, but also pass the index to the predicate function.
     @since 0.11 *)
 
+[@@@endif]
+
 val find_idx : f:('a -> bool) -> 'a t -> (int * 'a) option
 (** [find_idx ~f x] returns [Some (i,x)] where [x] is the [i]-th element of [l],
     and [f x] holds. Otherwise returns [None]. *)
@@ -501,11 +490,6 @@ val remove :
     @since 0.11 *)
 (* FIXME: the original CCList.mli uses ~x instead of ~key !! *)
 
-val filter_map : f:('a -> 'b option) -> 'a t -> 'b t
-(** [filter_map ~f l] is the sublist of [l] containing only elements for which
-    [f] returns [Some e].
-    Map and remove elements at the same time. *)
-
 val keep_some : 'a option t -> 'a t
 (** [keep_some l] retains only elements of the form [Some x].
     Like [filter_map CCFun.id].
@@ -612,16 +596,6 @@ val group_succ : eq:(('a -> 'a -> bool)[@keep_label]) -> 'a list -> 'a list list
 
 (** {2 Indices} *)
 
-val mapi : f:(int -> 'a -> 'b) -> 'a t -> 'b t
-(** [mapi ~f l] is like {!map}, but the function [f] is applied to the index of
-    the element as first argument (counting from 0), and the element
-    itself as second argument. *)
-
-val iteri : f:(int -> 'a -> unit) -> 'a t -> unit
-(** [iteri ~f l] is like {!iter}, but the function [f] is applied to the index of
-    the element as first argument (counting from 0), and the element
-    itself as second argument. *)
-
 val iteri2 : f:(int -> 'a -> 'b -> unit) -> 'a t -> 'b t -> unit
 (** [iteri2 ~f l1 l2] applies [f] to the two lists [l1] and [l2] simultaneously.
     The integer passed to [f] indicates the index of element.
@@ -900,11 +874,6 @@ val to_iter : 'a t -> 'a iter
 (** [to_iter l] returns a [iter] of the elements of the list [l].
     @since 2.8 *)
 
-val to_seq : 'a t -> 'a Seq.t
-(** [to_seq l] returns a [Seq.t] of the elements of the list [l].
-    Renamed from [to_std_seq] since 3.0.
-    @since 3.0 *)
-
 val of_iter : 'a iter -> 'a t
 (** [of_iter iter] builds a list from a given [iter].
     In the result, elements appear in the same order as they did in the source [iter].
@@ -915,12 +884,6 @@ val of_seq_rev : 'a Seq.t -> 'a t
     Renamed from [of_std_seq_rev] since 3.0.
     @since 3.0 *)
 
-val of_seq : 'a Seq.t -> 'a t
-(** [of_seq seq] builds a list from a given [Seq.t].
-    In the result, elements appear in the same order as they did in the source [Seq.t].
-    Renamed from [of_std_seq] since 3.0.
-    @since 3.0 *)
-
 val to_gen : 'a t -> 'a gen
 (** [to_gen l] returns a [gen] of the elements of the list [l]. *)
 
diff --git a/tests/core/t_float.ml b/tests/core/t_float.ml
index 0575b80c1..20bdda479 100644
--- a/tests/core/t_float.ml
+++ b/tests/core/t_float.ml
@@ -2,10 +2,10 @@ open CCFloat
 module T = (val Containers_testlib.make ~__FILE__ ())
 include T;;
 
-t @@ fun () -> max nan 1. = 1.;;
-t @@ fun () -> min nan 1. = 1.;;
-t @@ fun () -> max 1. nan = 1.;;
-t @@ fun () -> min 1. nan = 1.;;
+t @@ fun () -> is_nan (max nan 1.);;
+t @@ fun () -> is_nan (min nan 1.);;
+t @@ fun () -> is_nan (max 1. nan);;
+t @@ fun () -> is_nan (min 1. nan);;
 
 q
   Q.(pair float float)