I'm using Boost 1.49, and Visual Studio 10. I'm having a hard time figuring out how to store a shared_ptr to a derived class in a collection of shared_ptr to the base class. This is something I do all the time with normal shared pointers. This is my code: { struct Base {}; struct Derived : public Base {}; typedef boost::interprocess::managed_shared_ptr < Base, boost::interprocess::managed_shared_memory >::type Base_ptr; typedef boost::interprocess::deque < Base_ptr, boost::interprocess::managed_shared_memory::allocator< Base_ptr

::type > Queue;

struct shm_remove { shm_remove() { boost::interprocess::shared_memory_object::remove("testing"); } ~shm_remove() { boost::interprocess::shared_memory_object::remove("testing"); } } remover; boost::interprocess::managed_shared_memory shared_memory( boost::interprocess::create_only, "testing", 65536); Queue* queue = shared_memory.construct< Queue

(boost::interprocess::anonymous_instance)( shared_memory.get_allocator< Base_ptr >());

queue->push_back( bi::make_managed_shared_ptr< Derived >( shared_memory.construct< Derived >(bi::anonymous_instance)(), shared_memory)); } The compiler tells me a bunch of cryptic stuff, I think it has to do with the different deleter types: boost/container/deque.hpp(1040): error C2664: 'boost::interprocess::shared_ptr::shared_ptr(const boost::interprocess::offset_ptr &,const VoidAllocator &,const Deleter &)' : cannot convert parameter 1 from 'const boost::interprocess::shared_ptr' to 'const boost::interprocess::offset_ptr &' 5> with 5> [ 5> T=Base, 5> VoidAllocator=boost::interprocess::allocatorboost::interprocess::mutex_family,boost::interprocess::iset_index>>, 5> Deleter=boost::interprocess::deleterboost::interprocess::mutex_family,boost::interprocess::iset_index>>, 5> PointedType=Base, 5> DifferenceType=ptrdiff_t, 5> OffsetType=size_t, 5> OffsetAlignment=0 5> ] 5> and 5> [ 5> T=Derived, 5> VoidAllocator=boost::interprocess::allocatorboost::interprocess::mutex_family,boost::interprocess::iset_index>>, 5> Deleter=boost::interprocess::deleterboost::interprocess::mutex_family,boost::interprocess::iset_index>> 5> ] 5> and 5> [ 5> PointedType=Base, 5> DifferenceType=ptrdiff_t, 5> OffsetType=size_t, 5> OffsetAlignment=0 5> ] 5> Reason: cannot convert from 'const boost::interprocess::shared_ptr' to 'const boost::interprocess::offset_ptr' 5> with 5> [ 5> T=Derived, 5> VoidAllocator=boost::interprocess::allocatorboost::interprocess::mutex_family,boost::interprocess::iset_index>>, 5> Deleter=boost::interprocess::deleterboost::interprocess::mutex_family,boost::interprocess::iset_index>> 5> ] 5> and 5> [ 5> PointedType=Base, 5> DifferenceType=ptrdiff_t, 5> OffsetType=size_t, 5> OffsetAlignment=0 5> ] 5> No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called 5> test.cpp(94) : see reference to function template instantiation 'void boost::container::deque::push_back>(const BOOST_MOVE_TEMPL_PARAM &)' being compiled 5> with 5> [ 5> T=Base_ptr, 5> A=boost::interprocess::allocatorboost::interprocess::mutex_family,boost::interprocess::iset_index>>, 5> VoidAllocator=boost::interprocess::allocatorboost::interprocess::mutex_family,boost::interprocess::iset_index>>, 5> Deleter=boost::interprocess::deleterboost::interprocess::mutex_family,boost::interprocess::iset_index>>, 5> BOOST_MOVE_TEMPL_PARAM=boost::interprocess::shared_ptrboost::interprocess::mutex_family,boost::interprocess::iset_index>>,boost::interprocess::deleterboost::interprocess::mutex_family,boost::interprocess::iset_index>>> 5> ] --- Aaron Wright