Hi all, I see multiset is not present in boost interprocess, so I tried to use a "set" with a customized comparator to achieve multiset functionality. sample code: struct set_comparator { bool operator()(const int& a, const int& b) const { return a < b; // if change a <= b then seeing an errror } }; bip::shared_memory_object::remove("SHM"); bip::managed_shared_memory segment(bip::open_or_create, "SHM", 2047*1024*1024); typedef bip::allocator<int, bip::managed_shared_memory::segment_manager> ShmemAllocator; typedef bip::set<int, set_comparator, ShmemAllocator> ShmemSet; segment.destroy<ShmemSet>("MySet"); ShmemSet *sample1 = segment.construct<ShmemSet>("MySet")(set_comparator(), segment.get_segment_manager()); std::cout << "Insert in shared set:" << std::endl; sample1->insert(40); std::cout << "Insert in shared set:" << std::endl; sample1->insert(40); // Crashing here sample1->insert(40); sample1->insert(40); sample1->insert(20); sample1->insert(20); sample1->insert(20); sample1->insert(20); sample1->insert(20); when i try duplicate insertion, seeing following error, /usr/include/boost/intrusive/bstree.hpp:1331: boost::intrusive::bstree_impl<ValueTraits, VoidOrKeyOfValue, VoidOrKeyComp, SizeType, ConstantTimeSize, AlgoType, HeaderHolder>::iterator boost::intrusive::bstree_impl<ValueTraits, VoidOrKeyOfValue, VoidOrKeyComp, SizeType, ConstantTimeSize, AlgoType, HeaderHolder>::insert_unique_commit(boost::intrusive::bstree_impl<ValueTraits, VoidOrKeyOfValue, VoidOrKeyComp, SizeType, ConstantTimeSize, AlgoType, HeaderHolder>::reference, const insert_commit_data&) [with ValueTraits = boost::intrusive::bhtraits<boost::container::dtl::tree_node<int, boost::interprocess::offset_ptr<void>, boost::container::red_black_tree, true>, boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void>, true>, boost::intrusive::normal_link, boost::intrusive::dft_tag, 3>; VoidOrKeyOfValue = void; VoidOrKeyComp = boost::container::value_to_node_compare<boost::container::dtl::tree_node<int, boost::interprocess::offset_ptr<void>, boost::container::red_black_tree, true>, boost::intrusive::tree_value_compare<boost::interprocess::offset_ptr<int, long int, long unsigned int, 0>, main()::set_comparator, boost::move_detail::identity<int>, bool, true>, bool>; SizeType = long unsigned int; bool ConstantTimeSize = true; boost::intrusive::algo_types AlgoType = boost::intrusive::RbTreeAlgorithms; HeaderHolder = void; boost::intrusive::bstree_impl<ValueTraits, VoidOrKeyOfValue, VoidOrKeyComp, SizeType, ConstantTimeSize, AlgoType, HeaderHolder>::iterator = boost::intrusive::tree_iterator<boost::intrusive::bhtraits<boost::container::dtl::tree_node<int, boost::interprocess::offset_ptr<void>, boost::container::red_black_tree, true>, boost::intrusive::rbtree_node_traits<boost::interprocess::offset_ptr<void>, true>, boost::intrusive::normal_link, boost::intrusive::dft_tag, 3>, false>; boost::intrusive::bstree_impl<ValueTraits, VoidOrKeyOfValue, VoidOrKeyComp, SizeType, ConstantTimeSize, AlgoType, HeaderHolder>::reference = boost::container::dtl::tree_node<int, boost::interprocess::offset_ptr<void>, boost::container::red_black_tree, true>&; boost::intrusive::bstree_impl<ValueTraits, VoidOrKeyOfValue, VoidOrKeyComp, SizeType, ConstantTimeSize, AlgoType, HeaderHolder>::insert_commit_data = boost::intrusive::insert_commit_data_t<boost::interprocess::offset_ptr<boost::intrusive::compact_rbtree_node<boost::interprocess::offset_ptr<void>
, long int, long unsigned int, 0> >]: Assertion `( p == this->end() || !this->comp()(*p, value) )' failed.
"Need input on this or is this expected behaviour as per boost??" -- Regards, Murali Kishore