Re: [Boost-users] Can I return std::unique_ptr in a boost::future?

Subject: Re: [Boost-users] Can I return std::unique_ptr in a boost::future?
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2013-11-15 02:28:26

Le 15/11/13 02:05, Aaron_Wright_at_[hidden] a écrit :
> I'm trying to return a std::unique_ptr in a boost::future. I can't get it
> to compile. Is it possible? The code wraps a packaged_task in a functor to
> make it copyable enough to pass to a boost::asio::io_service, where the
> work will be done in another thread. The code works for other return types
> that are copyable.
>
> This is what I have for a small test case:
>
> std::unique_ptr< int > get_int_impl(int i)
> {
>     return std::unique_ptr< int >(new int(i));
> }
>
> std::unique_ptr< int > get_int(int i)
> {
>     typedef boost::packaged_task< std::unique_ptr< int > > Task;
>
>     boost::shared_ptr< Task > task = boost::make_shared< Task
>> (boost::bind(&get_int_impl, 42));
>     boost::unique_future< std::unique_ptr< int > > future =
> task->get_future(); // <--- Error from this line.
>
>     m_service.post(boost::bind(&Task::operator(), task));
>
>     return future.get();
> }
>
> BOOST_AUTO_TEST_CASE(test_get_int)
> {
>     BOOST_CHECK_EQUAL(*get_int(42), 42);
> }
>
> The error:
>
> boost/thread/future.hpp(239): error C2248:
> 'std::unique_ptr<_Ty>::unique_ptr' : cannot access private member declared
> in class 'std::unique_ptr<_Ty>'
> ---
>
>
Hi, please try defining BOOST_VERSION 4 and using boost::future instead 
and let me know.

Best,
Vicente