Re: [Boost-bugs] [Boost C++ Libraries] #3627: boost::asio::async_read() cannot be used with null_buffers()

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #3627: boost::asio::async_read() cannot be used with null_buffers()
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-01-12 21:46:23

#3627: boost::asio::async_read() cannot be used with null_buffers()
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 Reporter:  Dmitry Goncharov <dgoncharov@…>                     |       Owner:  chris_kohlhoff
     Type:  Feature Requests                                    |      Status:  new           
Milestone:  To Be Determined                                    |   Component:  asio          
  Version:  Boost 1.40.0                                        |    Severity:  Not Applicable
 Keywords:  asio async_read null_buffers                        |  
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Changes (by chris_kohlhoff):

  * type:  Bugs => Feature Requests
  * severity:  Problem => Not Applicable
  * milestone:  Boost 1.41.0 => To Be Determined

Comment:

 The null_buffers type is only intended for use with async_read_some() and
 async_write_some() on the "lowest layer", i.e. the socket or descriptor.
 It is not part of any of the stream type requirements, and so not
 supported by composed operations such as async_read.

 If it worked with the buffered*_stream<> templates then that was just a
 side effect of the 0-byte read/write bug.

 It may or may not be useful to support null_buffers as part of the stream
 type requirements. I'm reclassifying this as a feature request as
 something to think about in the future.

 In any case:

 {{{
 Right now I have no way to check for data (async) without reading it off
 the socket.
 }}}

 is not correct. It works just fine if you use async_read_some() on the
 socket.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3627#comment:3>
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