packaged_task<void()> errors

[alex85k]

I have these errors and can not fix them myself:

C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(1014): error C2182: '_Get_value' : illegal use of type 'void' [D:\build_d\libosmium\build-cmake\examples\osmium_area_test.vcxproj]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(1466) : see reference to class template instantiation 'std::_State_manager<_Ty>' being compiled
          with
          [
              _Ty=void
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(1747) : see reference to class template instantiation 'std::_Promise<_Ret>' being compiled
          with
          [
              _Ret=void
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(1747) : while compiling class template member function 'std::packaged_task<void (void)>::packaged_task(std::packaged_task<void (void)> &&) throw()'
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\type_traits(1545) : see reference to function template instantiation 'std::packaged_task<void (void)>::packaged_task(std::packaged_task<void (void)> &&) throw()' being compiled
          D:\build_d\libosmium\include\osmium/thread/checked_task.hpp(55) : see reference to class template instantiation 'std::packaged_task<void (void)>' being compiled
          D:\build_d\libosmium\include\osmium/io/reader.hpp(176) : see reference to function template instantiation 'osmium::thread::CheckedTask<osmium::io::detail::ReadThread>::CheckedTask<osmium::thread::Queue<std::string>&,osmium::io::Decompressor*,std::atomic<bool>&>(osmium::thread::Queue<std::string> &,osmium::io::Decompressor *&&,std::atomic<bool> &)' being compiled
          D:\build_d\libosmium\include\osmium/io/reader.hpp(176) : see reference to function template instantiation 'osmium::thread::CheckedTask<osmium::io::detail::ReadThread>::CheckedTask<osmium::thread::Queue<std::string>&,osmium::io::Decompressor*,std::atomic<bool>&>(osmium::thread::Queue<std::string> &,osmium::io::Decompressor *&&,std::atomic<bool> &)' being compiled
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(1021): error C2182: '_Val' : illegal use of type 'void' [D:\build_d\libosmium\build-cmake\examples\osmium_area_test.vcxproj]
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(1029): error C2182: '_Val' : illegal use of type 'void' [D:\build_d\libosmium\build-cmake\examples\osmium_area_test.vcxproj]
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(1747): error C2665: 'std::forward' : none of the 2 overloads could convert all the argument types [D:\build_d\libosmium\build-cmake\examples\osmium_area_test.vcxproj]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\type_traits(1509): could be '_Ty &&std::forward<std::_Promise<_Ret>>(std::_Promise<_Ret> &&) throw()'
          with
          [
              _Ty=std::_Promise<void>
  ,            _Ret=void
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\type_traits(1503): or       '_Ty &&std::forward<std::_Promise<_Ret>>(std::_Promise<_Ret> &)'
          with
          [
              _Ty=std::_Promise<void>
  ,            _Ret=void
          ]
          while trying to match the argument list '(std::_Promise<int>)'
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(1749): error C2512: 'std::_Promise<int>' : no appropriate default constructor available [D:\build_d\libosmium\build-cmake\examples\osmium_area_test.vcxproj]
  osmium_convert.cpp

This is known to be an error or standard unclearness about packaged_task<void()>:
http://stackoverflow.com/questions/14744588/why-is-stdpackaged-taskvoid-not-valid

We had to add a workaround for this in OSRM:
Project-OSRM/osrm-backend@42d3ee9
Project-OSRM/osrm-backend#998 (comment)
in libosmium it seems much harder...

My half-fixed branch (with cmake-building of examples by build.bat):
https://github.com/alex85k/libosmium

[joto]

@alex85k: Can you verify this works now?

[alex85k]

Yes, this seems to be fixed. Thank you!

[alex85k]

Sorry, it is not so clear - different task-related error showed:

C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\xrefwrap(269): error C2280: 'std::_Callable_base<_Ty,false>::_Callable_base(const std::_Callable_base<_Ty,false> &)' : attempting to reference a deleted function [D:\build_d\libosmium2\build-cmake\examples\osmium_area_test.vcxproj]
          with
          [
              _Ty=osmium::io::detail::XMLParser
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\xrefwrap(198) : compiler has generated 'std::_Callable_base<_Ty,false>::_Callable_base' here
          with
          [
              _Ty=osmium::io::detail::XMLParser
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\functional(180) : see reference to function template instantiation 'std::_Callable_obj<osmium::io::detail::XMLParser,false>::_Callable_obj<_Callable&>(_Ty2)' being compiled
          with
          [
              _Callable=_MyWrapper
  ,            _Ty2=_MyWrapper &
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\functional(180) : see reference to function template instantiation 'std::_Callable_obj<osmium::io::detail::XMLParser,false>::_Callable_obj<_Callable&>(_Ty2)' being compiled
          with
          [
              _Callable=_MyWrapper
  ,            _Ty2=_MyWrapper &
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\functional(177) : while compiling class template member function 'std::_Func_impl<_MyWrapper,_Alloc,_Ret,>::_Func_impl(std::_Func_impl<_MyWrapper,_Alloc,_Ret,> &)'
          with
          [
              _Alloc=std::allocator<std::_Func_class<bool,>>
  ,            _Ret=bool
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\functional(209) : see reference to function template instantiation 'std::_Func_impl<_MyWrapper,_Alloc,_Ret,>::_Func_impl(std::_Func_impl<_MyWrapper,_Alloc,_Ret,> &)' being compiled
          with
          [
              _Alloc=std::allocator<std::_Func_class<bool,>>
  ,            _Ret=bool
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\functional(495) : see reference to class template instantiation 'std::_Func_impl<_MyWrapper,_Alloc,_Ret,>' being compiled
          with
          [
              _Alloc=std::allocator<std::_Func_class<bool,>>
  ,            _Ret=bool
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\functional(396) : see reference to function template instantiation 'void std::_Func_class<_Ret,>::_Do_alloc<_Myimpl,_Ty,_Alloc>(_Fty &&,_Alloc)' being compiled
          with
          [
              _Ret=bool
  ,            _Ty=osmium::io::detail::XMLParser
  ,            _Alloc=std::allocator<std::_Func_class<bool,>>
  ,            _Fty=osmium::io::detail::XMLParser
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\functional(396) : see reference to function template instantiation 'void std::_Func_class<_Ret,>::_Do_alloc<_Myimpl,_Ty,_Alloc>(_Fty &&,_Alloc)' being compiled
          with
          [
              _Ret=bool
  ,            _Ty=osmium::io::detail::XMLParser
  ,            _Alloc=std::allocator<std::_Func_class<bool,>>
  ,            _Fty=osmium::io::detail::XMLParser
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\functional(385) : see reference to function template instantiation 'void std::_Func_class<_Ret,>::_Reset_alloc<_Ty,std::allocator<std::_Func_class<_Ret,>>>(_Fty &&,_Alloc)' being compiled
          with
          [
              _Ret=bool
  ,            _Ty=osmium::io::detail::XMLParser
  ,            _Fty=osmium::io::detail::XMLParser
  ,            _Alloc=std::allocator<std::_Func_class<bool,>>
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\functional(385) : see reference to function template instantiation 'void std::_Func_class<_Ret,>::_Reset_alloc<_Ty,std::allocator<std::_Func_class<_Ret,>>>(_Fty &&,_Alloc)' being compiled
          with
          [
              _Ret=bool
  ,            _Ty=osmium::io::detail::XMLParser
  ,            _Fty=osmium::io::detail::XMLParser
  ,            _Alloc=std::allocator<std::_Func_class<bool,>>
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\functional(671) : see reference to function template instantiation 'void std::_Func_class<_Ret,>::_Reset<_Ty>(_Fty &&)' being compiled
          with
          [
              _Ret=bool
  ,            _Ty=osmium::io::detail::XMLParser
  ,            _Fty=osmium::io::detail::XMLParser
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\functional(671) : see reference to function template instantiation 'void std::_Func_class<_Ret,>::_Reset<_Ty>(_Fty &&)' being compiled
          with
          [
              _Ret=bool
  ,            _Ty=osmium::io::detail::XMLParser
  ,            _Fty=osmium::io::detail::XMLParser
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(588) : see reference to function template instantiation 'std::function<_Ret (void)>::function<_Ty>(_Fx &&)' being compiled
          with
          [
              _Ret=bool
  ,            _Ty=osmium::io::detail::XMLParser
  ,            _Fx=osmium::io::detail::XMLParser
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(588) : see reference to function template instantiation 'std::function<_Ret (void)>::function<_Ty>(_Fx &&)' being compiled
          with
          [
              _Ret=bool
  ,            _Ty=osmium::io::detail::XMLParser
  ,            _Fx=osmium::io::detail::XMLParser
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(1742) : see reference to function template instantiation 'std::_Packaged_state<_Ret (void)>::_Packaged_state<_Ty>(_Fty2 &&)' being compiled
          with
          [
              _Ret=bool
  ,            _Ty=osmium::io::detail::XMLParser
  ,            _Fty2=osmium::io::detail::XMLParser
          ]
          C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\include\future(1744) : see reference to function template instantiation 'std::_Packaged_state<_Ret (void)>::_Packaged_state<_Ty>(_Fty2 &&)' being compiled
          with
          [
              _Ret=bool
  ,            _Ty=osmium::io::detail::XMLParser
  ,            _Fty2=osmium::io::detail::XMLParser
          ]
          D:\build_d\libosmium2\include\osmium/thread/checked_task.hpp(55) : see reference to function template instantiation 'std::packaged_task<bool (void)>::packaged_task<osmium::io::detail::XMLParser>(_Fty2 &&)' being compiled
          with
          [
              _Fty2=osmium::io::detail::XMLParser
          ]
          D:\build_d\libosmium2\include\osmium/thread/checked_task.hpp(55) : see reference to function template instantiation 'std::packaged_task<bool (void)>::packaged_task<osmium::io::detail::XMLParser>(_Fty2 &&)' being compiled
          with
          [
              _Fty2=osmium::io::detail::XMLParser
          ]
          D:\build_d\libosmium2\include\osmium/io/detail/xml_input_format.hpp(602) : see reference to function template instantiation 'osmium::thread::CheckedTask<osmium::io::detail::XMLParser>::CheckedTask<osmium::thread::Queue<std::string>&,osmium::thread::Queue<osmium::memory::Buffer>&,std::promise<osmium::io::Header>&,osmium::osm_entity_bits::type&,std::atomic<bool>&>(osmium::thread::Queue<std::string> &,osmium::thread::Queue<osmium::memory::Buffer> &,std::promise<osmium::io::Header> &,osmium::osm_entity_bits::type &,std::atomic<bool> &)' being compiled
          D:\build_d\libosmium2\include\osmium/io/detail/xml_input_format.hpp(602) : see reference to function template instantiation 'osmium::thread::CheckedTask<osmium::io::detail::XMLParser>::CheckedTask<osmium::thread::Queue<std::string>&,osmium::thread::Queue<osmium::memory::Buffer>&,std::promise<osmium::io::Header>&,osmium::osm_entity_bits::type&,std::atomic<bool>&>(osmium::thread::Queue<std::string> &,osmium::thread::Queue<osmium::memory::Buffer> &,std::promise<osmium::io::Header> &,osmium::osm_entity_bits::type &,std::atomic<bool> &)' being compiled

[joto]

Difficult to see what the problem here is. Maybe it is missing a move constructor here?

Try adding XMLInputFormat(XMLInputFormat&& other) = default; to the XMLInputFormat class declaration.

[alex85k]

Tried this - no result, the same errors.
Adding XMLParser(XMLParser&& other) = default; to XMLParser did not help too...

[joto]

@alex85k: Can you verify this is fixed by the last commit?

[alex85k]

Yes, it was fixed, thank you!

[alex85k]

The same error showed up for OPLOutputBlock :)
Trying to add analogous copy-constructor.

[alex85k]

Added something to compile: alex85k@6e430a1
( please rework )