Change as_tuple to propagate an initiation object's executor.

asio/include/asio/impl/as_tuple.hpp

@@ -21,6 +21,7 @@
 #include "asio/associator.hpp"
 #include "asio/async_result.hpp"
 #include "asio/detail/handler_cont_helpers.hpp"
+#include "asio/detail/initiation_base.hpp"
 #include "asio/detail/type_traits.hpp"
 
 #include "asio/detail/push_options.hpp"
@@ -119,23 +120,27 @@ struct async_result<as_tuple_t<CompletionToken>, Signatures...>
       typename detail::as_tuple_signature<Signatures>::type...>
 {
   template <typename Initiation>
-  struct init_wrapper
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    init_wrapper(Initiation init)
-      : initiation_(static_cast<Initiation&&>(init))
+    using detail::initiation_base<Initiation>::initiation_base;
+
+    template <typename Handler, typename... Args>
+    void operator()(Handler&& handler, Args&&... args) &&
     {
+      static_cast<Initiation&&>(*this)(
+          detail::as_tuple_handler<decay_t<Handler>>(
+            static_cast<Handler&&>(handler)),
+          static_cast<Args&&>(args)...);
     }
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args)
+    void operator()(Handler&& handler, Args&&... args) const &
     {
-      static_cast<Initiation&&>(initiation_)(
+      static_cast<const Initiation&>(*this)(
           detail::as_tuple_handler<decay_t<Handler>>(
             static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
-
-    Initiation initiation_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>