From fa40cf88255c3f3ba9e24532ec243fe35061a2e6 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Fri, 18 Oct 2024 12:56:43 -0400
Subject: [PATCH] doc

---
 src/core/fut.mli | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/core/fut.mli b/src/core/fut.mli
index 03e3c728..b6682b1c 100644
--- a/src/core/fut.mli
+++ b/src/core/fut.mli
@@ -34,9 +34,9 @@ val make_promise : unit -> 'a promise
 (** Same as {!make} but returns a single promise (which can be upcast to a
     future). This is useful mostly to preserve memory.
 
-  How to upcast to a future:
+  How to upcast to a future in the worst case:
   {[let prom = Fut.make_promise();;
-    let fut: _ Fut.t = (prom :> _ Fut.t)
+    let fut = (prom : _ Fut.promise :> _ Fut.t) ;;
   ]}
   @since NEXT_RELEASE *)