Re: [Boost-bugs] [Boost C++ Libraries] #10340: No boost::promise<T>::set_value(const T&) overload present in C++03 mode

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #10340: No boost::promise<T>::set_value(const T&) overload present in C++03 mode
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-08-30 10:06:49

#10340: No boost::promise<T>::set_value(const T&) overload present in C++03 mode
-------------------------------+----------------------
  Reporter:  rob.desbois@…     |      Owner:  anthonyw
      Type:  Bugs              |     Status:  new
 Milestone:  To Be Determined  |  Component:  thread
   Version:  Boost 1.54.0      |   Severity:  Problem
Resolution:                    |   Keywords:
-------------------------------+----------------------
Description changed by viboes:

Old description:

> When compiling in C++03 mode I am unable to use anything but a primitive
> type in a promise, and therefore also the dependent types in Boost.Thread
>
> Minimal testcase:
>     #include <boost/thread/future.hpp>
>
>     struct foo
>     {
>         foo(int i_): i(i_) {}
>         int i;
>     };
>
>     int main()
>     {
>         // Clearly a const future ref isn't much use, but I needed to
>         // prove the problem wasn't me trying to copy a unique_future
>
>         const boost::unique_future<foo>& fut =
> boost::make_ready_future( foo(42) );
>     }
>

> Output from g++ 4.8.2 with Boost 1.55 and -DBOOST_THREAD_USES_MOVE:
>     In file included from
> ../../deps/boost/include/boost/tuple/tuple.hpp:33:0,
>                      from
> ../../deps/boost/include/boost/thread/detail/async_func.hpp:37,
>                      from
> ../../deps/boost/include/boost/thread/future.hpp:22,
>                      from t.cpp:2:
>     ../../deps/boost/include/boost/tuple/detail/tuple_basic.hpp: In
> function ‘typename boost::tuples::access_traits<typename
> boost::tuples::element<N, boost::tuples::cons<HT, TT>
> >::type>::const_type boost::tuples::get(const boost::tuples::cons<HT,
> TT>&)’:
>     ../../deps/boost/include/boost/tuple/detail/tuple_basic.hpp:228:45:
> warning: typedef ‘cons_element’ locally defined but not used [-Wunused-
> local-typedefs]
>        typedef BOOST_DEDUCED_TYPENAME impl::type cons_element;
>                                                  ^
>     In file included from
> ../../deps/boost/include/boost/bind/bind.hpp:29:0,
>                      from ../../deps/boost/include/boost/bind.hpp:22,
>                      from
> ../../deps/boost/include/boost/thread/future.hpp:41,
>                      from t.cpp:2:
>     ../../deps/boost/include/boost/bind/arg.hpp: In constructor
> ‘boost::arg<I>::arg(const T&)’:
>     ../../deps/boost/include/boost/bind/arg.hpp:37:22: warning: typedef
> ‘T_must_be_placeholder’ locally defined but not used [-Wunused-local-
> typedefs]
>              typedef char T_must_be_placeholder[ I ==
> is_placeholder<T>::value? 1: -1 ];
>                           ^
>     t.cpp: In function ‘int main()’:
>     t.cpp:12:78: error: expected primary-expression before ‘f’
>              const boost::unique_future<foo>& fut =
> boost::make_ready_future( foo f(42) );
> ^
>     t.cpp:12:42: warning: unused variable ‘fut’ [-Wunused-variable]
>              const boost::unique_future<foo>& fut =
> boost::make_ready_future( foo f(42) );
>                                               ^
>     In file included from
> ../../deps/boost/include/boost/system/system_error.hpp:14:0,
>                      from
> ../../deps/boost/include/boost/thread/exceptions.hpp:22,
>                      from
> ../../deps/boost/include/boost/thread/pthread/mutex.hpp:12,
>                      from
> ../../deps/boost/include/boost/thread/mutex.hpp:16,
>                      from
> ../../deps/boost/include/boost/thread/future.hpp:24,
>                      from t.cpp:2:
>     ../../deps/boost/include/boost/system/error_code.hpp: At global
> scope:
>     ../../deps/boost/include/boost/system/error_code.hpp:222:36: warning:
> ‘boost::system::posix_category’ defined but not used [-Wunused-variable]
>          static const error_category &  posix_category =
> generic_category();
>                                         ^
>     ../../deps/boost/include/boost/system/error_code.hpp:223:36: warning:
> ‘boost::system::errno_ecat’ defined but not used [-Wunused-variable]
>          static const error_category &  errno_ecat     =
> generic_category();
>                                         ^
>     ../../deps/boost/include/boost/system/error_code.hpp:224:36: warning:
> ‘boost::system::native_ecat’ defined but not used [-Wunused-variable]
>          static const error_category &  native_ecat    =
> system_category();
>

> I have replicated this with Clang 3.4, also with Boost 1.54 on both
> compilers, and without -DBOOST_THREAD_USES_MOVE too.
> From the boost-users mailing list it looks like it has been replicated
> with 1.56 too.

New description:

 When compiling in C++03 mode I am unable to use anything but a primitive
 type in a promise, and therefore also the dependent types in Boost.Thread

 Minimal testcase:


 {{{
     #include <boost/thread/future.hpp>

     struct foo
     {
         foo(int i_): i(i_) {}
         int i;
     };

     int main()
     {
         // Clearly a const future ref isn't much use, but I needed to
         // prove the problem wasn't me trying to copy a unique_future

         const boost::unique_future<foo>& fut = boost::make_ready_future(
 foo(42) );
     }
 }}}



 Output from g++ 4.8.2 with Boost 1.55 and -DBOOST_THREAD_USES_MOVE:
     In file included from
 ../../deps/boost/include/boost/tuple/tuple.hpp:33:0,
                      from
 ../../deps/boost/include/boost/thread/detail/async_func.hpp:37,
                      from
 ../../deps/boost/include/boost/thread/future.hpp:22,
                      from t.cpp:2:
     ../../deps/boost/include/boost/tuple/detail/tuple_basic.hpp: In
 function ‘typename boost::tuples::access_traits<typename
 boost::tuples::element<N, boost::tuples::cons<HT, TT> >::type>::const_type
 boost::tuples::get(const boost::tuples::cons<HT, TT>&)’:
     ../../deps/boost/include/boost/tuple/detail/tuple_basic.hpp:228:45:
 warning: typedef ‘cons_element’ locally defined but not used [-Wunused-
 local-typedefs]
        typedef BOOST_DEDUCED_TYPENAME impl::type cons_element;
                                                  ^
     In file included from
 ../../deps/boost/include/boost/bind/bind.hpp:29:0,
                      from ../../deps/boost/include/boost/bind.hpp:22,
                      from
 ../../deps/boost/include/boost/thread/future.hpp:41,
                      from t.cpp:2:
     ../../deps/boost/include/boost/bind/arg.hpp: In constructor
 ‘boost::arg<I>::arg(const T&)’:
     ../../deps/boost/include/boost/bind/arg.hpp:37:22: warning: typedef
 ‘T_must_be_placeholder’ locally defined but not used [-Wunused-local-
 typedefs]
              typedef char T_must_be_placeholder[ I ==
 is_placeholder<T>::value? 1: -1 ];
                           ^
     t.cpp: In function ‘int main()’:
     t.cpp:12:78: error: expected primary-expression before ‘f’
              const boost::unique_future<foo>& fut =
 boost::make_ready_future( foo f(42) );
 ^
     t.cpp:12:42: warning: unused variable ‘fut’ [-Wunused-variable]
              const boost::unique_future<foo>& fut =
 boost::make_ready_future( foo f(42) );
                                               ^
     In file included from
 ../../deps/boost/include/boost/system/system_error.hpp:14:0,
                      from
 ../../deps/boost/include/boost/thread/exceptions.hpp:22,
                      from
 ../../deps/boost/include/boost/thread/pthread/mutex.hpp:12,
                      from
 ../../deps/boost/include/boost/thread/mutex.hpp:16,
                      from
 ../../deps/boost/include/boost/thread/future.hpp:24,
                      from t.cpp:2:
     ../../deps/boost/include/boost/system/error_code.hpp: At global scope:
     ../../deps/boost/include/boost/system/error_code.hpp:222:36: warning:
 ‘boost::system::posix_category’ defined but not used [-Wunused-variable]
          static const error_category &  posix_category =
 generic_category();
                                         ^
     ../../deps/boost/include/boost/system/error_code.hpp:223:36: warning:
 ‘boost::system::errno_ecat’ defined but not used [-Wunused-variable]
          static const error_category &  errno_ecat     =
 generic_category();
                                         ^
     ../../deps/boost/include/boost/system/error_code.hpp:224:36: warning:
 ‘boost::system::native_ecat’ defined but not used [-Wunused-variable]
          static const error_category &  native_ecat    =
 system_category();


 I have replicated this with Clang 3.4, also with Boost 1.54 on both
 compilers, and without -DBOOST_THREAD_USES_MOVE too.
 From the boost-users mailing list it looks like it has been replicated
 with 1.56 too.

--
-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10340#comment:7>
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