Re: [boost] asio formal review

From: Eugene Alterman (eugalt_at_[hidden])
Date: 2005-12-12 13:37:56

"Christopher Kohlhoff" <chris_at_[hidden]> wrote in message 
news:20051212114532.54650.qmail_at_web32604.mail.mud.yahoo.com...
> Hi Eugene,
>
> --- Eugene Alterman <eugalt_at_[hidden]> wrote:
> <snip>
>> The bottom line of my suggestion is to have 2 distinct
>> interfaces. One is for stream establishment and connection
>> properties management. It provides efficient protocol stack
>> layer navigation and access (but no stream i/o operations).
>> The other one is strictly layered streaming interface for data
>> transfer.
>>
>> Do you think it makes sense?
>
> Could you sketch out some rough code illustrating what you are
> thinking of? I'm having trouble seeing how it would fit
> together, in particular how you would transition from one
> interface the other.

Hi Chris,

I will call this interfaces core_socket and stream_socket respectively.
You always start with an object of a stream_socket class and then obtain a 
reference to core_socket from it.

Let us first start with a design that does not change the current interface 
of stream_socket. Define a new core_socket class template, and derive 
stream_socket from it adding the stream functionality. Then we can define 
lowest_layer_type as core_socket. This will solve the stream layering 
problem since having a reference to core_socket of a lower layer would not 
allow performing stream operations on it.

The next step would be to derive stream_socket privately from core_socket 
and provide a public member function returning a reference to core_socket.
This would deal with any temptation to downcast a core_socket reference to 
stream_socket.

I hope I made myself clear now,
Eugene.