[Boost-bugs] [Boost C++ Libraries] #8714: Allow move-only handlers

Subject: [Boost-bugs] [Boost C++ Libraries] #8714: Allow move-only handlers
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-06-20 10:42:15

#8714: Allow move-only handlers
---------------------------------+----------------------------
 Reporter:  Marton <marton78@…>  |      Owner:  chris_kohlhoff
     Type:  Feature Requests     |     Status:  new
Milestone:  To Be Determined     |  Component:  asio
  Version:  Boost 1.53.0         |   Severity:  Problem
 Keywords:                       |
---------------------------------+----------------------------
 (See also http://stackoverflow.com/questions/17211263)

 The requirement that handlers be copy constructible doesn't allow for the
 following idiom:

 {{{
 void connection::send_response()
 {
     // block until previous response is sent
     std::unique_lock<std::mutex> locker(response_mutex_);

     // prepare response
     response_ = "foo";

     // send response back to caller. move the unique_lock into the binder
     // to keep the mutex locked until asio is done sending.
     asio::async_write(stream_,
                       asio::const_buffers_1(response_.data(),
 response_.size()),
                       std::bind(&connection::response_sent,
 shared_from_this(),
                                 _1, _2, std::move(locker))
                       );
 }

 void connection::response_sent(const boost::system::error_code& err,
 std::size_t len)
 {
     if (err) handle_error(err);
     // the mutex is unlocked when the binder is destroyed
 }
 }}}

 Please remove this restriction, there is no reason for it when using
 C++11.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/8714>
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