[boost] [asio] Const/Mutable_Buffers concept

I see that there's both Const/Mutable_Buffers Concept, but there isnt any Buffer concept in asio. Why is that? What if I want to create a more customized buffer/buffers, how could I do? It seems to be impossible, since the buffer must be inherited or convertible to boost::asio::buffer / const_buffer. And there isnt any Buffer concept so that it could explain how a buffer could be extensible. IMO, It would be good to have a Buffer concept, so that the Buffers/Buffer concepts could be reused by the application or third-party libraries. BTW, shouldnt related functions state the functions namespaces? Best regards, -- Felipe Magno de Almeida