Fixed async_connection::write() SFINAE-isation

Overloaded function selection based on ConstBufferSeq::value_type.
http_server_async_less_copy test fixed accordingly.

Author: omalashenko

boost/network/protocol/http/server/async_connection.hpp

@@ -214,15 +214,15 @@ namespace boost { namespace network { namespace http {
         }
 
         template <class Range, class Callback>
-        typename disable_if<is_base_of<asio::const_buffer, Range>, void>::type
+        typename disable_if<is_base_of<asio::const_buffer, typename Range::value_type>, void>::type
         write(Range const & range, Callback const & callback) {
             lock_guard lock(headers_mutex);
             if (error_encountered) boost::throw_exception(boost::system::system_error(*error_encountered));
             write_impl(boost::make_iterator_range(range), callback);
         }
 
         template <class ConstBufferSeq, class Callback>
-        typename enable_if<is_base_of<asio::const_buffer, ConstBufferSeq>, void>::type
+        typename enable_if<is_base_of<asio::const_buffer, typename ConstBufferSeq::value_type>, void>::type
         write(ConstBufferSeq const & seq, Callback const & callback)
         {
             write_vec_impl(seq, callback, shared_array_list(), shared_buffers());

libs/network/test/http_server_async_less_copy.cpp

@@ -6,6 +6,8 @@
 
 #define BOOST_TEST_MODULE HTTP Asynchronous Server Tests
 
+#include <vector>
+
 #include <boost/config/warning_disable.hpp>
 #include <boost/network/include/http/server.hpp>
 #include <boost/network/utils/thread_pool.hpp>
@@ -51,9 +53,9 @@ struct async_hello_world {
             static char const * hello_world = "Hello, World!";
             connection->set_status(server::connection::ok);
             connection->set_headers(boost::make_iterator_range(headers, headers+3));
-            connection->write(
-                    boost::asio::const_buffers_1(hello_world, 13)
-                    , boost::bind(&async_hello_world::error, this, _1));
+            std::vector<boost::asio::const_buffer> iovec;
+            iovec.push_back(boost::asio::const_buffer(hello_world, 13));
+            connection->write(iovec, boost::bind(&async_hello_world::error, this, _1));
         }
     }