From ad00d616e8ed3dc3e7b1e8fb4a8681e5b4eca0e8 Mon Sep 17 00:00:00 2001
From: Sizhe Zhao <prc.zhao@outlook.com>
Date: Sat, 27 Jun 2020 22:51:48 +0800
Subject: [PATCH] Warn about calling wrappers at compile time until #14049 is
 fixed. (#14828)

---
 doc/manual.rst | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/doc/manual.rst b/doc/manual.rst
index da50e2c56..9f5252ae0 100644
--- a/doc/manual.rst
+++ b/doc/manual.rst
@@ -843,7 +843,10 @@ language features:
 * closure iterators
 * the ``cast`` operator
 * reference (pointer) types
-* the FFI
+* FFI
+
+The use of wrappers that use FFI and/or ``cast`` is also disallowed. Note that
+these wrappers include the ones in the standard libraries.
 
 Some or all of these restrictions are likely to be lifted over time.