boost :: unordered_map使用boost :: interprocess :: cached_node_allocator編譯失敗

Question

我想在boost :: interprocess :: managed_shared_memory段創建一個boost :: unordered_map。這工作正常，直到我試圖改變使用boost :: interprocess :: allocator boost :: interprocess :: cached_node_allocator。

似乎hash_bucket結構推遲了密鑰大小計算，但cached_node_allocator在編譯時需要大小。關於如何使這項工作的任何想法？

樣品的編號：

#include <boost/interprocess/managed_shared_memory.hpp> 
#include <boost/interprocess/segment_manager.hpp> 
#include <boost/interprocess/containers/string.hpp> 
#include <boost/interprocess/allocators/cached_node_allocator.hpp> 
#include <boost/unordered_map.hpp> 

using namespace boost::interprocess; 

int main() 
{ 
    //Create shared memory. 
    managed_shared_memory segment(create_only, 
           "SharedMem", //segment name 
           65536); 

    // Define cached node allocator type for char in a shared memory segment. 
    typedef boost::interprocess:: 
     cached_node_allocator<char, 
     managed_shared_memory::segment_manager> cached_node_allocator_t; 

    // Define an interprocess string type which uses the cached node allocator. 
    typedef boost::interprocess:: 
     basic_string<char, std::char_traits<char>, 
     cached_node_allocator_t> shared_string_t; 

    // Get an instance of the allocator. 
    cached_node_allocator_t allocator_instance(
     segment.get_segment_manager()); 

    // Create an unordered map with Key and Value as interprocess strings, 
    // using the default hash and predicate and use the cached node allocator. 
    boost::unordered_map<shared_string_t, shared_string_t, 
         boost::hash<shared_string_t>, 
         std::equal_to<shared_string_t>, 
         cached_node_allocator_t> my_map_t(allocator_instance); 

    return 0; 
} 

GCC輸出：

$ g++ -I/opt/local/include cnasum.cc 
/opt/local/include/boost/interprocess/allocators/detail/allocator_common.hpp: In instantiation of ‘const size_t boost::interprocess::sizeof_value<boost::unordered_detail::hash_bucket<boost::interprocess::cached_node_allocator<std::pair<const boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >::value’: 
/opt/local/include/boost/interprocess/allocators/cached_node_allocator.hpp:104: instantiated from ‘boost::interprocess::cached_node_allocator<boost::unordered_detail::hash_bucket<boost::interprocess::cached_node_allocator<std::pair<const boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul>’ 
/opt/local/include/boost/unordered/detail/fwd.hpp:134: instantiated from ‘boost::unordered_detail::hash_bucket<boost::interprocess::cached_node_allocator<std::pair<const boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >’ 
/opt/local/include/boost/unordered/detail/fwd.hpp:278: instantiated from ‘boost::unordered_detail::hash_iterator_base<boost::interprocess::cached_node_allocator<std::pair<const boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul>, boost::unordered_detail::ungrouped>’ 
/opt/local/include/boost/unordered/detail/fwd.hpp:347: instantiated from ‘boost::unordered_detail::hash_buckets<boost::interprocess::cached_node_allocator<std::pair<const boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul>, boost::unordered_detail::ungrouped>’ 
/opt/local/include/boost/unordered/detail/fwd.hpp:921: instantiated from ‘boost::unordered_detail::types<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, std::pair<const boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::hash<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, std::equal_to<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::interprocess::cached_node_allocator<std::pair<const boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul>, boost::unordered_detail::map_extractor<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, std::pair<const boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > > >, boost::unordered_detail::ungrouped>’ 
/opt/local/include/boost/unordered/detail/unique.hpp:125: instantiated from ‘boost::unordered_detail::map<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::hash<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, std::equal_to<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::interprocess::cached_node_allocator<std::pair<const boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >’ 
/opt/local/include/boost/unordered/unordered_map.hpp:63: instantiated from ‘boost::unordered_map<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::hash<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, std::equal_to<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >’ 
cnasum.cc:35: instantiated from here 
/opt/local/include/boost/interprocess/allocators/detail/allocator_common.hpp:43: error: invalid application of ‘sizeof’ to incomplete type ‘boost::unordered_detail::hash_bucket<boost::interprocess::cached_node_allocator<std::pair<const boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >, boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::cached_node_allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index>, 64ul> >’ 
$ 

Answer 1

爲unordered_map的構造必須採取幾個參數：

typedef boost::unordered_map<...> map_type; 

map_type m(100,        // number of buckets 
      boost::hash<shared_string_t>(), // hasher object, pass temporary by value 
      std::equal_to<shared_string_t>(), // predicate object, ditto 
      allocator_instance    // your allocator object 
     );