diff --git a/src/core/CCArray.ml b/src/core/CCArray.ml
index 87a439d7..ddd13c4c 100644
--- a/src/core/CCArray.ml
+++ b/src/core/CCArray.ml
@@ -52,6 +52,16 @@ let get_safe a i =
   None (get_safe [|1;2;3|] ~-42)
 *)
 
+let map_inplace f a =
+  Array.iteri (fun i e -> Array.unsafe_set a i (f e)) a
+
+(*$Q
+  Q.(array int) (fun a -> \
+    let b = map ((+) 1) a in \
+    map_inplace ((+) 1) a; \
+    b = a)
+*)
+
 let fold = Array.fold_left
 
 let foldi f acc a =
diff --git a/src/core/CCArray.mli b/src/core/CCArray.mli
index 34f95264..d6b496c6 100644
--- a/src/core/CCArray.mli
+++ b/src/core/CCArray.mli
@@ -58,6 +58,9 @@ val get_safe : 'a t -> int -> 'a option
 (** [get_safe a i] returns [Some a.(i)] if [i] is a valid index.
     @since 0.18 *)
 
+val map_inplace : ('a -> 'a) -> 'a t -> unit
+(** [map_inplace f a] replace all elements of [a] by its image by [f]. *)
+
 val fold : ('a -> 'b -> 'a) -> 'a -> 'b t -> 'a
 (** [fold f init a] computes [f (… (f (f init a.(0)) a.(1)) …) a.(n-1)],
     where [n] is the length of the array [a].
diff --git a/src/core/CCArrayLabels.mli b/src/core/CCArrayLabels.mli
index 8be4f679..b9c5b1b6 100644
--- a/src/core/CCArrayLabels.mli
+++ b/src/core/CCArrayLabels.mli
@@ -32,17 +32,17 @@ type 'a t = 'a array
 [@@@else_]
 
 include module type of ArrayLabels
-(** {{: http://caml.inria.fr/pub/docs/manual-ocaml/libref/ArrayLabels.html} Documentation for the standard ArrayLabels module}*)
-
-module Floatarray = CCArray.Floatarray
-type 'a t = 'a array
 (** @inline
     {{: https://caml.inria.fr/pub/docs/manual-ocaml/libref/Array.html} Documentation for the standard Array module}*)
 
+module Floatarray = CCArray.Floatarray
+
+type 'a t = 'a array
+
 [@@@endif]
 
 val empty : 'a t
-(** [empty] is the empty array, physically equal to [||]. *)
+(** [empty] is the empty array, physically equal to [[||]]. *)
 
 val equal : 'a equal -> 'a t equal
 (** [equal eq a1 a2] is [true] if the lengths of [a1] and [a2] are the same
@@ -59,6 +59,9 @@ val get_safe : 'a t -> int -> 'a option
 (** [get_safe a i] returns [Some a.(i)] if [i] is a valid index.
     @since 0.18 *)
 
+val map_inplace : f:('a -> 'a) -> 'a t -> unit
+(** [map_inplace ~f a] replace all elements of [a] by its image by [f]. *)
+
 val fold : f:('a -> 'b -> 'a) -> init:'a -> 'b t -> 'a
 (** [fold ~f ~init a] computes [f (… (f (f init a.(0)) a.(1)) …) a.(n-1)],
     where [n] is the length of the array [a].