boost.interprocess seems to have a bug.

[635716742]

I would like to use boost.interprocess in a way similar to the "code" below, but encountered a compile error. Upon analysis, it seems that the problem arises from the STL having two partial specializations for the template indirectly_readable_traits, which require the parameter to either contain value_type or element_type. However, in boost::interprocess::offset_ptr, both value_type and element_type are present simultaneously, leading to template ambiguity during instantiation. I am hoping for a solution or guidance on how to correctly use boost.interprocess in conjunction with the STL.

code

    boost::interprocess::shared_memory_object::remove("shm_name");
    boost::interprocess::managed_shared_memory segment(boost::interprocess::create_only, "shm_name", 65536);

    boost::interprocess::allocator<int, boost::interprocess::managed_shared_memory::segment_manager> myAllocator(segment.get_segment_manager());
    using KWVector = std::vector<int, boost::interprocess::allocator<int, boost::interprocess::managed_shared_memory::segment_manager>>;
    KWVector* pMyVec = segment.construct<KWVector>("MyVector")(myAllocator);
    pMyVec->push_back(12);
    pMyVec->push_back(34);

compile error

/usr/include/c++/10/bits/iterator_concepts.h: In substitution of ‘template<class _Tp> using __iter_value_t = typename std::__detail::__iter_traits_impl<_Tp, std::indirectly_readable_traits<_Iter> >::type::value_type [with _Tp = boost::interprocess::offset_ptr<int, long int, long unsigned int, 0>]’:
/usr/include/c++/10/bits/iterator_concepts.h:259:11:   required by substitution of ‘template<class _Tp> using iter_value_t = std::__detail::__iter_value_t<typename std::remove_cv<typename std::remove_reference<_Tp>::type>::type> [with _Tp = boost::interprocess::offset_ptr<int, long int, long unsigned int, 0>]’
/usr/include/c++/10/bits/stl_iterator.h:1301:13:   required from ‘class std::move_iterator<boost::interprocess::offset_ptr<int, long int, long unsigned int, 0> >’
/usr/include/c++/10/bits/stl_uninitialized.h:347:3:   required from ‘_ForwardIterator std::__uninitialized_move_if_noexcept_a(_InputIterator, _InputIterator, _ForwardIterator, _Allocator&) [with _InputIterator = boost::interprocess::offset_ptr<int, long int, long unsigned int, 0>; _ForwardIterator = boost::interprocess::offset_ptr<int, long int, long unsigned int, 0>; _Allocator = boost::interprocess::allocator<int, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family>, boost::interprocess::iset_index> >]’
/usr/include/c++/10/bits/vector.tcc:474:3:   required from ‘void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp, _Alloc>::iterator, _Args&& ...) [with _Args = {int}; _Tp = int; _Alloc = boost::interprocess::allocator<int, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family>, boost::interprocess::iset_index> >; std::vector<_Tp, _Alloc>::iterator = std::vector<int, boost::interprocess::allocator<int, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family>, boost::interprocess::iset_index> > >::iterator]’
/usr/include/c++/10/bits/vector.tcc:121:21:   required from ‘std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {int}; _Tp = int; _Alloc = boost::interprocess::allocator<int, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family>, boost::interprocess::iset_index> >; std::vector<_Tp, _Alloc>::reference = int&]’
/usr/include/c++/10/bits/stl_vector.h:1204:21:   required from ‘void std::vector<_Tp, _Alloc>::push_back(std::vector<_Tp, _Alloc>::value_type&&) [with _Tp = int; _Alloc = boost::interprocess::allocator<int, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family>, boost::interprocess::iset_index> >; std::vector<_Tp, _Alloc>::value_type = int]’
/mnt/d/src/ShareConfig/src/main.cpp:21:26:   required from here
/usr/include/c++/10/bits/iterator_concepts.h:254:13: error: ambiguous template instantiation for ‘struct std::indirectly_readable_traits<boost::interprocess::offset_ptr<int, long int, long unsigned int, 0> >’
  254 |       using __iter_value_t = typename
      |             ^~~~~~~~~~~~~~
/usr/include/c++/10/bits/iterator_concepts.h:242:12: note: candidates are: ‘template<class _Tp>  requires requires{typename _Tp::value_type;} struct std::indirectly_readable_traits<_Iter> [with _Tp = boost::interprocess::offset_ptr<int, long int, long unsigned int, 0>]’
  242 |     struct indirectly_readable_traits<_Tp>
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/bits/iterator_concepts.h:247:12: note:                 ‘template<class _Tp>  requires requires{typename _Tp::element_type;} struct std::indirectly_readable_traits<_Iter> [with _Tp = boost::interprocess::offset_ptr<int, long int, long unsigned int, 0>]’
  247 |     struct indirectly_readable_traits<_Tp>
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/bits/iterator_concepts.h:254:13: error: invalid use of incomplete type ‘std::__detail::__iter_traits<boost::interprocess::offset_ptr<int, long int, long unsigned int, 0>, std::indirectly_readable_traits<boost::interprocess::offset_ptr<int, long int, long unsigned int, 0> > >’ {aka ‘struct std::indirectly_readable_traits<boost::interprocess::offset_ptr<int, long int, long unsigned int, 0> >’}
  254 |       using __iter_value_t = typename
      |             ^~~~~~~~~~~~~~
/usr/include/c++/10/bits/iterator_concepts.h:225:29: note: declaration of ‘std::__detail::__iter_traits<boost::interprocess::offset_ptr<int, long int, long unsigned int, 0>, std::indirectly_readable_traits<boost::interprocess::offset_ptr<int, long int, long unsigned int, 0> > >’ {aka ‘struct std::indirectly_readable_traits<boost::interprocess::offset_ptr<int, long int, long unsigned int, 0> >’}
  225 |   template<typename> struct indirectly_readable_traits { };

STL and boost sound code

c++ file iterator_concepts.h:

  template<typename _Tp> requires requires { typename _Tp::value_type; }
    struct indirectly_readable_traits<_Tp>
    : __detail::__cond_value_type<typename _Tp::value_type>
    { };

  template<typename _Tp> requires requires { typename _Tp::element_type; }
    struct indirectly_readable_traits<_Tp>
    : __detail::__cond_value_type<typename _Tp::element_type>
    { };

boost file offset_ptr.hpp:

   typedef PointedType                       element_type;
   typedef PointedType *                     pointer;
   typedef typename ipcdetail::
      add_reference<PointedType>::type       reference;
   typedef typename ipcdetail::
      remove_volatile<typename ipcdetail::
         remove_const<PointedType>::type
            >::type                          value_type;
   typedef DifferenceType                    difference_type;
   typedef std::random_access_iterator_tag   iterator_category;
   typedef OffsetType                        offset_type;

My ENV:

ubuntu20.04 gcc (Ubuntu 10.3.0-1ubuntu1~20.04) 10.3.0 boost version 1.71( I also used 1.83) c++version: c++2a

[addy90]

Instead of std::vector you have to use boost::interprocess::vector, please see https://www.boost.org/doc/libs/1_83_0/doc/html/interprocess/allocators_containers.html#interprocess.allocators_containers.containers_explained. This is because of incompatibilities such as the one you encountered. More about these and further issues with the STL containers are in the docs linked.

[pliniofpa]

This issue should be closed now.