add invoke() in orderr to support calling member fn

include/boost/fiber/detail/invoke.hpp

@@ -0,0 +1,48 @@
+
+//          Copyright Oliver Kowalke 2014.
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE_1_0.txt or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_FIBERS_DETAIL_INVOKE_H
+#define BOOST_FIBERS_DETAIL_INVOKE_H
+
+#include <functional>
+#include <type_traits>
+#include <utility>
+
+#include <boost/config.hpp>
+
+#ifdef BOOST_HAS_ABI_HEADERS
+# include BOOST_ABI_PREFIX
+#endif
+
+namespace boost {
+namespace fibers {
+namespace detail {
+
+template< typename Fn, typename... Args >
+typename std::enable_if<
+    std::is_member_pointer< typename std::decay< Fn >::type >::value,
+    typename std::result_of< Fn&&( Args && ...) >::type
+>::type
+invoke( Fn && fn, Args && ... args) {
+    return std::mem_fn( fn)( std::forward< Args >( args) ...);
+}
+
+template< typename Fn, typename ... Args >
+typename std::enable_if<
+    ! std::is_member_pointer< typename std::decay< Fn >::type >::value,
+    typename std::result_of< Fn&&( Args && ...) >::type
+>::type
+invoke( Fn && fn, Args && ... args) {
+    return std::forward< Fn >( fn)( std::forward< Args >( args) ...);
+}
+
+}}}
+
+#ifdef BOOST_HAS_ABI_HEADERS
+#include BOOST_ABI_SUFFIX
+#endif
+
+#endif // BOOST_FIBERS_DETAIL_INVOKE_H

include/boost/fiber/fiber_context.hpp

@@ -24,6 +24,7 @@
 
 #include <boost/fiber/detail/config.hpp>
 #include <boost/fiber/detail/fss.hpp>
+#include <boost/fiber/detail/invoke.hpp>
 #include <boost/fiber/detail/spinlock.hpp>
 #include <boost/fiber/detail/scheduler.hpp>
 #include <boost/fiber/fiber_manager.hpp>
@@ -122,7 +123,7 @@ private:
               [=,fn=std::forward< Fn >( fn_),tpl=std::forward< Tpl >( tpl_)] () mutable {
                 try {
                     BOOST_ASSERT( is_running() );
-                    fn(
+                    detail::invoke( fn,
                         // std::tuple_element<> does not perfect forwarding
                         std::forward< decltype( std::get< I >( std::declval< Tpl >() ) ) >(
                             std::get< I >( std::forward< Tpl >( tpl) ) ) ... );