wrapping a string/shared_ptr unordered_map with map_indexing_suite in boost python

Question

I'm trying to wrap a boost::unordered_map using the map_indexing_suite utility in boost python. However, anytime I attempt to do so, I'm encountering the error

Error   26  error C2039: 'key_comp' : is not a member of 'boost::unordered::unordered_map<K,T>' c:\programming_libraries\cpp_libraries\boost_1_49_0\boost\python\suite\indexing\map_indexing_suite.hpp  155

Here's the wrapping I'm doing

class_<boost::unordered_map<std::string, boost::shared_ptr<Character::BaseCharacter> > >("BasePartyMemberMap")
                .def(map_indexing_suite<boost::unordered_map<std::string, boost::shared_ptr<Character::BaseCharacter> > >())
                ;

I'm assuming this has something to do with the unordered_map being used in conjunction with the shared_ptr. If I use an std::map it works correctly. I was hoping someone could tell me what the issue is and if it's resolvable. I'd rather not switch the structure to an std::map if I can avoid it.

Answer 1

Boost.Python does not support std::unordered_map and movement semantics till v.1.55 (see Boost Version 1.55.0 Release Notes, "Multi-index Containers" section). So you can either use latest version or imlement one of the next:

• Implement map_indexing_suite for unordered_map, main difference is that keys are unordered, so you should remove compare_index from the original implementation: www.boost.org/doc/libs/1_54_0/boost/python/suite/indexing/map_indexing_suite.hpp
• Use this sample https://wiki.python.org/moin/boost.python/StlContainers to make simple own wrapper