Re: [Boost-users] [thread] Internal compiler error when trying to make movable future

Le 06/09/13 04:54, Gavin Lambert a écrit :

Am I doing something wrong in the following code?

#include

template<typename T> struct test_node { BOOST_THREAD_MOVABLE_ONLY(test_node)

typedef boost::unique_future future_node;

T value; future_node next; };

(In the "real code" I've defined move constructors etc as well of course, but they don't affect the result so I've omitted them for brevity.)

Using boost v1.53 with BOOST_THREAD_VERSION==2 and VS2008 (non C++11 compiler), the above code produces an internal compiler error:

1>t:\boost\boost_1_53_0\boost\type_traits\is_convertible.hpp(484) : fatal error C1001: An internal error has occurred in the compiler. 1>(compiler file 'msc1.cpp', line 1411) 1> To work around this problem, try simplifying or changing the program near the locations listed above. 1>Please choose the Technical Support command on the Visual C++ 1> Help menu, or open the Technical Support help file for more information 1> t:\boost\boost_1_53_0\boost\thread\detail\is_convertible.hpp(22) : see reference to class template instantiation 'boost::is_convertible' being compiled 1> with 1> [ 1> From=test_node<int> &, 1> To=boost::detail::thread_move_t 1> ] 1> t:\boost\boost_1_53_0\boost\mpl\if.hpp(63) : see reference to class template instantiation 'boost::thread_detail::is_convertible' being compiled 1> with 1> [ 1> T1=test_node<int> &, 1> T2=boost::detail::thread_move_t 1> ] 1> t:\boost\boost_1_53_0\boost\thread\future.hpp(519) : see reference to class template instantiation 'boost::mpl::if_' being compiled 1> with 1> [ 1> T1=boost::thread_detail::is_convertible>, 1> T2=boost::detail::thread_move_t, 1> T3=const test_node<int> & 1> ] 1> t:\boost\boost_1_53_0\boost\thread\future.hpp(1398) : see reference to class template instantiation 'boost::detail::future_traits<T>' being compiled 1> with 1> [ 1> T=test_node<int> 1> ] 1> s:\tests\nodetest.cpp(26) : see reference to class template instantiation 'boost::unique_future<R>' being compiled 1> with 1> [ 1> R=test_node<int> 1> ] 1> s:\tests\nodetest.cpp(56) : see reference to class template instantiation 'test_node<T>' being compiled 1> with 1> [ 1> T=int 1> ]

The internal error goes away if I remove the MOVABLE_ONLY macro or the future_node instance field. The equivalent move code (using boost::detail::thread_move_t directly) for boost 1.47 compiles and works successfully (but crashes again if I switch to boost 1.53).

Is this a regression in boost or am I doing something incorrect somewhere? Does anyone know of a workaround?

Note that it does not matter if I try to use Boost.Move syntax instead, as unique_future<> internally uses Boost.Thread's move implementation, which is where things seem to be failing.

One possible issue is that I'm trying to declare a future to an incomplete type (because it's self-referential), which is possibly confusing some of the internal checks it wants to do. But again, this usage used to work, and I'm not sure how to fix it given the new boost version. At least not without introducing pointers and heap allocation, which I really didn't want to do.

Hi, please,could you post a complete example so that I can try to reproduce it. best, Vicente