Add CArray.copy

src/ctypes/ctypes.mli

@@ -317,8 +317,11 @@ sig
       used to initialise every element of the array.  The argument [?finalise],
       if present, will be called just before the memory is freed. *)
 
+  val copy : 'a t -> 'a t
+  (** [copy a] creates a fresh array with the same elements as [a]. *)
+
   val element_type : 'a t -> 'a typ
-(** Retrieve the element type of an array. *)
+  (** Retrieve the element type of an array. *)
 end
 (** Operations on C arrays. *)
 

src/ctypes/ctypes_memory.ml

@@ -199,6 +199,14 @@ struct
         | None -> arr
         | Some v -> fill arr v; arr
 
+  let copy {astart = CPointer src; alength} =
+    begin
+      let reftyp = Fat.reftype src in
+      let CPointer dst as r = allocate_n reftyp alength in
+      let () = Stubs.memcpy ~dst ~src ~size:(alength * sizeof reftyp) in
+      from_ptr r alength
+    end
+
   let element_type { astart } = reference_type astart
 
   let of_list typ list =

tests/test-arrays/test_array.ml

@@ -159,6 +159,24 @@ let test_fold_right _ =
   let r = CArray.fold_right (fun _ -> assert false) a [] in
   assert_equal r []
 
+(*
+  Test the CArray.copy function
+ *)
+let test_copy _ =
+  let a = CArray.of_list int [1; 2; 3] in
+  let r = CArray.copy a in
+
+  begin
+    assert_equal [1; 2; 3] (CArray.to_list a);
+    assert_equal [1; 2; 3] (CArray.to_list r);
+    CArray.set r 0 10;
+    assert_equal [1; 2; 3] (CArray.to_list a);
+    assert_equal [10; 2; 3] (CArray.to_list r);
+    CArray.set a 1 20;
+    assert_equal [1; 20; 3] (CArray.to_list a);
+    assert_equal [10; 2; 3] (CArray.to_list r);
+  end
+
 
 (*
   Test that creating an array initializes all elements appropriately.
@@ -286,6 +304,9 @@ let suite = "Array tests" >:::
    "CArray.fold_right"
     >:: test_fold_right;
 
+   "CArray.copy"
+    >:: test_copy;
+
    "array initialization"
     >:: test_array_initialiation;