Use bind_front_handler:

The implementation uses bind_front_handler to reduce the
resources consumed when instantiating templates during
compilation.

include/boost/beast/core/impl/buffered_read_stream.ipp

@@ -126,7 +126,7 @@ read_some_op<MutableBufferSequence, Handler>::operator()(
         step_ = 3;
         return boost::asio::post(
             s_.get_executor(),
-            bind_handler(std::move(*this), ec, 0));
+            bind_front_handler(std::move(*this), ec, 0));
 
     case 1:
         // upcall