1 files changed, 7 insertions, 0 deletions
diff --git a/stdlib/set.ml b/stdlib/set.ml
index 262629253..4e1f4be8c 100644
--- a/stdlib/set.ml
+++ b/stdlib/set.ml
@@ -47,6 +47,7 @@ module type S =
     val max_elt: t -> elt
     val choose: t -> elt
     val split: elt -> t -> t * bool * t
+    val find: elt -> t -> elt
   end
 
 module Make(Ord: OrderedType) =
@@ -348,4 +349,10 @@ module Make(Ord: OrderedType) =
 
     let choose = min_elt
 
+    let rec find x = function
+        Empty -> raise Not_found
+      | Node(l, v, r, _) ->
+          let c = Ord.compare x v in
+          if c = 0 then v
+          else find x (if c < 0 then l else r)
   end