cleanup and more tests in CCHeap

src/core/CCHeap.ml

@@ -64,6 +64,19 @@ end
   )
 *)
 
+(* test filter *)
+(*$QR & ~count:30
+  Q.(list_of_size Gen.(return 1_000) int) (fun l ->
+    (* put elements into a heap *)
+    let h = H.of_seq (Sequence.of_list l) in
+    let h = H.filter (fun x->x mod 2=0) h in
+    OUnit.assert_bool "all odd"
+      (H.to_seq h |> Sequence.for_all (fun x -> x mod 2 = 0));
+    let l' = extract_list h in
+    is_sorted l'
+  )
+*)
+
 module type S = sig
   type elt
   type t