Boost C++ Libraries: Ticket #4521: Error using boost::move on packaged_task (MSVC 10)

component, milestone changed; owner set

Marshall Clow — Mon, 15 Nov 2010 22:20:43 GMT

owner set to Anthony Williams
component None → thread
milestone Boost 1.44.0 → To Be Determined

summary changed; cc set

viboes — Wed, 17 Nov 2010 20:12:40 GMT

cc viboes added
summary Error using boost::move on packaged_task → Error using boost::move on packaged_task (MSVC 10)

Claudio Bley — Wed, 02 Nov 2011 11:34:17 GMT

This example also fails with GCC 4.5.4 and 4.6.1 using -std=c++0x:

g++ -std=c++0x answer.cc -I /home/claudio/aux/include/boost-1_47/
In file included from /home/claudio/aux/include/boost-1_47/boost/thread/thread.hpp:22:0,
                 from /home/claudio/aux/include/boost-1_47/boost/thread.hpp:13,
                 from answer.cc:1:
/home/claudio/aux/include/boost-1_47/boost/thread/future.hpp: In constructor ‘boost::detail::thread_data<F>::thread_data(F&) [with F = boost::packaged_task<int>]’:
/home/claudio/aux/include/boost-1_47/boost/thread/pthread/thread_heap_alloc.hpp:24:47:   instantiated from ‘T* boost::detail::heap_new(A1&&) [with T = boost::detail::thread_data<boost::packaged_task<int> >, A1 = boost::packaged_task<int>&]’
/home/claudio/aux/include/boost-1_47/boost/thread/detail/thread.hpp:130:146:   instantiated from ‘static boost::detail::thread_data_ptr boost::thread::make_thread_info(F&&) [with F = boost::packaged_task<int>&, boost::detail::thread_data_ptr = boost::shared_ptr<boost::detail::thread_data_base>]’
/home/claudio/aux/include/boost-1_47/boost/thread/detail/thread.hpp:168:62:   instantiated from ‘boost::thread::thread(F&&) [with F = boost::packaged_task<int>&]’
answer.cc:17:36:   instantiated from here
/home/claudio/aux/include/boost-1_47/boost/thread/future.hpp:1268:9: error: ‘boost::packaged_task<R>::packaged_task(boost::packaged_task<R>&) [with R = int, boost::packaged_task<R> = boost::packaged_task<int>]’ is private
/home/claudio/aux/include/boost-1_47/boost/thread/detail/thread.hpp:49:21: error: within this context

There are only 2 overloads of boost::move, and these don't work for a packaged_task.

boost::move should be equivalent to std::move ifndef BOOST_NO_RVALUE_REFERENCES, shouldn't it?

Simply

namespace boost {
  using std::move;
}

works with MSVC 10 and GCC 4.5, 4.6.

keywords set

viboes — Sun, 11 Dec 2011 11:39:48 GMT

keywords move added

There is an action point to use Boost.Move. Could we consider this as a duplicate of #6194 Adapt to Boost.Move.

viboes — Wed, 14 Dec 2011 22:48:29 GMT

If we follows the reference documentation, the example should not works as the functor (in this case a packaged task) must be copyable.

Thread Constructor
template<typename Callable>
thread(Callable func);
Preconditions:
    Callable must by copyable.
Effects:
    func is copied into storage managed internally by the thread library, and that copy is invoked on a newly-created thread of execution. If this invocation results in an exception being propagated into the internals of the thread library that is not of type boost::thread_interrupted, then std::terminate() will be called.
Postconditions:
    *this refers to the newly created thread of execution.
Throws:
    boost::thread_resource_error if an error occurs.
Thread Constructor with arguments
template <class F,class A1,class A2,...>
thread(F f,A1 a1,A2 a2,...);
Preconditions:
    F and each An must by copyable or movable.
Effects:
    As if thread(boost::bind(f,a1,a2,...)). Consequently, f and each an are copied into internal storage for access by the new thread.
Postconditions:
    *this refers to the newly created thread of execution.
Throws:
    boost::thread_resource_error if an error occurs.
Note:
    Currently up to nine additional arguments a1 to a9 can be specified in addition to the function f.

This doesn't means that the library shouldn't provide such a feature as otherwise it is unable to work with packaged_task. I have created a feature request for this purpose #6270 c++11 compliance: Add thread constructor from movable callable and movable arguments.

viboes — Sat, 31 Dec 2011 17:58:22 GMT

I have tested on trunk with msvc.10 and it is working. Could you give a try on trunk?

owner, status changed

viboes — Sat, 07 Jan 2012 23:43:46 GMT

owner changed from Anthony Williams to viboes
status new → assigned

milestone changed

viboes — Tue, 17 Jan 2012 07:01:19 GMT

milestone To Be Determined → Boost 1.49.0

Committed in trunk at revision [76543].

status, milestone changed; resolution set

viboes — Mon, 28 May 2012 16:42:34 GMT

status assigned → closed
resolution → fixed
milestone Boost 1.49.0 → Boost 1.50.0

Committed in release branch at [78543]