Adding inheritance hierarchy for asynchronous tags, and a support metafunction that checks if a tag is asynchronous.

deanberris · deanberris · commit 60af89c17fbc · 2010-06-10T17:40:14.000+08:00
diff --git a/boost/network/support/is_async.hpp b/boost/network/support/is_async.hpp
@@ -0,0 +1,27 @@
+#ifndef BOOST_NETWORK_SUPPORT_IS_ASYNC_HPP_20100608
+#define BOOST_NETWORK_SUPPORT_IS_ASYNC_HPP_20100608
+
+// Copyright 2010 (c) Dean Michael Berris
+// Copyright 2010 (c) Sinefunc, Inc.
+// 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)
+
+#include <boost/network/tags.hpp>
+#include <boost/type_traits/is_base_of.hpp>
+
+namespace boost { namespace network {
+
+    template <class Tag>
+    struct is_async :
+        is_base_of<
+            tags::async,
+            Tag
+        >
+    {};
+
+} // namespace network
+
+} // namespace boost
+
+#endif //BOOST_NETWORK_SUPPORT_IS_ASYNC_HPP_2010608
diff --git a/boost/network/tags.hpp b/boost/network/tags.hpp
@@ -10,13 +10,16 @@
 
 namespace boost { namespace network { namespace tags {
 
+    struct async {};
+
 struct default_string {};
 struct default_wstring {};
 struct http_default_8bit_tcp_resolve {};
 struct http_default_8bit_udp_resolve {};
 struct http_keepalive_8bit_tcp_resolve {};
 struct http_keepalive_8bit_udp_resolve {};
 struct http_server {};
+struct http_async_8bit_udp_resolve : async {};
 
 typedef default_string default_;
 
