add missing decay_copy.hpp

include/boost/fiber/detail/decay_copy.hpp

@@ -0,0 +1,36 @@
+
+//          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_FIBER_DETAIL_DECAY_COPY_H
+#define BOOST_FIBER_DETAIL_DECAY_COPY_H
+
+#include <type_traits>
+
+#include <boost/config.hpp>
+
+#include <boost/context/detail/config.hpp>
+
+#ifdef BOOST_HAS_ABI_HEADERS
+# include BOOST_ABI_PREFIX
+#endif
+
+namespace boost {
+namespace fibers {
+namespace detail {
+
+template< typename T >
+typename std::decay< T >::type
+decay_copy( T && t) {
+    return std::forward< T >( t);
+}
+
+}}}
+
+#ifdef BOOST_HAS_ABI_HEADERS
+#include BOOST_ABI_SUFFIX
+#endif
+
+#endif // BOOST_FIBER_DETAIL_DECAY_COPY_H