Add beast::asio::ssl_bundle workaround:

This works around the limitation that 1.56 boost::asio::ssl::stream objects
do not support r-value move or construction. It is required when the stream
does not own the socket.

beast/asio/ssl_bundle.h

@@ -0,0 +1,57 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_ASIO_SSL_BUNDLE_H_INCLUDED
+#define BEAST_ASIO_SSL_BUNDLE_H_INCLUDED
+
+#include <boost/asio/ip/tcp.hpp>
+#include <boost/asio/ssl/stream.hpp>
+#include <utility>
+
+namespace beast {
+namespace asio {
+
+/** Work-around for non-movable boost::ssl::stream.
+    This allows ssl::stream to be movable and allows the stream to
+    construct from an already-existing socket.
+*/
+struct ssl_bundle
+{
+    typedef boost::asio::ip::tcp::socket socket_type;
+    typedef boost::asio::ssl::stream <socket_type&> stream_type;
+
+    template <class... Args>
+    ssl_bundle (boost::asio::ssl::context& context, Args&&... args);
+
+    socket_type socket;
+    stream_type stream;
+};
+
+template <class... Args>
+ssl_bundle::ssl_bundle (boost::asio::ssl::context& context,
+    Args&&... args)
+    : socket(std::forward<Args>(args)...)
+    , stream (socket, context)
+{
+}
+
+} // asio
+} // beast
+
+#endif