Update for Net-TS Asio (API Change):

fix #769

The following classes are removed:

* handler_type
* async_result
* async_completion
* is_dynamic_buffer
* is_const_buffer_sequence
* is_mutable_buffer_sequence
* handler_alloc

Actions Required:

* Use BOOST_ASIO_HANDLER_TYPE instead of handler_type
* Use BOOST_ASIO_INITFN_RESULT_TYPE instead of async_result
* Use boost::asio::async_completion
* Use boost::asio::is_dynamic_buffer
* Use boost::asio::is_const_buffer_sequence
* Use boost::asio::is_mutable_buffer_sequence
* boost::asio::associated_allocator_t replaces handler_alloc

test/bench/buffers/bench_buffers.cpp

@@ -67,15 +67,13 @@ public:
     fill(MutableBufferSequence const& buffers)
     {
         std::size_t n = 0;
-        using boost::asio::buffer_cast;
-        using boost::asio::buffer_size;
-        for(boost::asio::mutable_buffer buffer : buffers)
+        for(auto b : beast::detail::buffers_range(buffers))
         {
             std::fill(
-                buffer_cast<char*>(buffer),
-                buffer_cast<char*>(buffer) +
-                    buffer_size(buffer), '\0');
-            n += buffer_size(buffer);
+                reinterpret_cast<char*>(b.data()),
+                reinterpret_cast<char*>(b.data()) +
+                    b.size(), '\0');
+            n += b.size();
         }
         return n;
     }