id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
7654,offset_ptr can't be evaluated a pointer to a container in shared memory,hongchenbo@…,Ion Gaztañaga,"i created a container(boost::container::set) in shared memory by managed_shared_memeory::construct,i wanted to put the pointer of container into a offset_ptr，codes as：
typedef boost::container::set<int, less<int>, int_allocator_type> values_type;
values_ptr_ = segment_manager_->construct<values_type>( boost::interprocess::anonymous_instance )( std::less<int>(), int_allocator_type( segment_manager_ ) );

when compiling：
error C2512: 'boost::interprocess::allocator<T,SegmentManager>' : no appropriate default constructor available
          with
          [
              T=boost::container::container_detail::rbtree_node<unsigned __int64,boost::interprocess::offset_ptr<void>>,
              SegmentManager=segment_manager_type
          ]

the related codes as：
template <class T>
   offset_ptr( T *ptr
             , typename ipcdetail::enable_if< ipcdetail::is_convertible<T*, PointedType*> >::type * = 0)
   {  this->set_offset(static_cast<PointedType*>(ptr)); }

template <bool B, class T = void>
struct enable_if_c {
  typedef T type;
};

template <class T>
struct enable_if_c<false, T> {};

template <class Cond, class T = void>
struct enable_if : public enable_if_c<Cond::value, T> {};

template <class Cond, class T = void>
struct disable_if : public enable_if_c<!Cond::value, T> {};

template <class T, class U>
class is_convertible
{
   typedef char true_t;
   class false_t { char dummy[2]; };
   static true_t dispatch(U);
   static false_t dispatch(...);
   static T trigger();
   public:
   static const bool value = sizeof(dispatch(trigger())) == sizeof(true_t);
};

i thougnt that T and U are values_type*,it's unnecessary to instantiate a values_type,but why called allocator's constructor ？

the boost::container's allocator must have a default constructor，but,in fact,boost::interprocess::allocator is stateful，its constructor need the pointer to segment_manager。is it a bug? or my codes is fault?",Bugs,closed,To Be Determined,interprocess,Boost 1.52.0,Problem,worksforme,offset_ptr boost::container,