From c7ef5c6f645d612335f72f01d5c90642bbe74780 Mon Sep 17 00:00:00 2001
From: Denis Blank <denis.blank@outlook.com>
Date: Mon, 10 Dec 2018 06:07:43 +0100
Subject: [PATCH] Adhust the SFO buffer size so it can contain a pointer at
 zero cost

---
 include/continuable/continuable-trait.hpp | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/include/continuable/continuable-trait.hpp b/include/continuable/continuable-trait.hpp
index 4e69507..318f694 100644
--- a/include/continuable/continuable-trait.hpp
+++ b/include/continuable/continuable-trait.hpp
@@ -70,11 +70,17 @@ public:
 
   /// The continuable type for the given parameters.
   using continuable = continuable_base<
-      ContinuationWrapper<sizeof(detail::base::ready_continuation<Args...>),
-                          void(promise),                   //
-                          bool(is_ready_arg_t) const,      //
-                          std::tuple<Args...>(query_arg_t) //
-                          >,
+      ContinuationWrapper<
+          // Size the buffer for the small functor optimization so the
+          // result itself fits in and guarantee that a pointer can
+          // fit in as well.
+          (sizeof(detail::base::ready_continuation<Args...>) < sizeof(void*)
+               ? sizeof(void*)
+               : sizeof(detail::base::ready_continuation<Args...>)),
+          void(promise),                   //
+          bool(is_ready_arg_t) const,      //
+          std::tuple<Args...>(query_arg_t) //
+          >,
       detail::traits::identity<Args...>>;
 };
 /// \}