I would have thought, naively enough, that one of the common uses of a bimap was that one should be able to create a bimap from a std::map as long as the relation between the two types was unique both ways. I was disconcerted when I did not see a bimap constructor that accepted a std::map of the same types, but then I saw the constructor which takes two iterators and decided to try that, like so: std::map<int,std::string> myMap; // ... fill myMap boost::bimap<int,std::string> myBimap(myMap.begin(),myMap.end()); I was met with, in VC9 using Boost 1.40: "c:\utilities\boost\boost_1_40_0\boost\multi_index_container.hpp(232) : error C2664: 'std::pair<_Ty1,_Ty2> boost::multi_index::multi_index_container<Value,IndexSpecifierList,Allocator>::insert_(const Value &,boost::multi_index::detail::ordered_index_node<Super> *)' : cannot convert parameter 1 from 'std::pair<_Ty1,_Ty2>' to 'const boost::bimaps::relation::mutant_relation<TA,TB,Info,force_mutable> &' 1> with 1> [ 1> _Ty1=boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<boost::bimaps::relation::mutant_relation<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info,true>,std::allocator<boost::bimaps::relation::mutant_relation<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info,true>>>>> *, 1> _Ty2=bool, 1> Value=boost::bimaps::relation::mutant_relation<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info,true>, 1> IndexSpecifierList=boost::bimaps::detail::bimap_core<int,TString,boost::mpl::na,boost::mpl::na,boost::mpl::na>::core_indices, 1> Allocator=std::allocator<boost::bimaps::relation::mutant_relation<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info,true>>, 1> Super=boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<boost::bimaps::relation::mutant_relation<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info,true>,std::allocator<boost::bimaps::relation::mutant_relation<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info,true>>>> 1> ] 1> and 1> [ 1> _Ty1=const int, 1> _Ty2=TString 1> ] 1> and 1> [ 1> TA=boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>, 1> TB=boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>, 1> Info=boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info, 1> force_mutable=true 1> ] 1> Reason: cannot convert from 'std::pair<_Ty1,_Ty2>' to 'const boost::bimaps::relation::mutant_relation<TA,TB,Info,force_mutable>' 1> with 1> [ 1> _Ty1=const int, 1> _Ty2=TString 1> ] 1> and 1> [ 1> TA=boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>, 1> TB=boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>, 1> Info=boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info, 1> force_mutable=true 1> ] 1> No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called 1> c:\utilities\boost\boost_1_40_0\boost\bimap\bimap.hpp(247) : see reference to function template instantiation 'boost::multi_index::multi_index_container<Value,IndexSpecifierList,Allocator>::multi_index_container<InputIterator>(InputIterator,InputIterator,const boost::tuples::cons<HT,TT> &,const std::allocator<_Ty> &)' being compiled 1> with 1> [ 1> Value=boost::bimaps::relation::mutant_relation<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info,true>, 1> IndexSpecifierList=boost::bimaps::detail::bimap_core<int,TString,boost::mpl::na,boost::mpl::na,boost::mpl::na>::core_indices, 1> Allocator=std::allocator<boost::bimaps::relation::mutant_relation<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info,true>>, 1> InputIterator=std::_Tree<std::_Tmap_traits<int,TString,std::less<int>,std::allocator<std::pair<const int,TString>>,false>>::iterator, 1> HT=boost::tuples::tuple<boost::multi_index::member<boost::bimaps::relation::detail::relation_storage<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,true>,std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,pointer-to-member(0x4)>,std::less<std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>>>, 1> TT=boost::tuples::cons<boost::tuples::tuple<boost::multi_index::member<boost::bimaps::relation::detail::relation_storage<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,true>,int,pointer-to-member(0x0)>,std::less<int>>,boost::multi_index::detail::index_base<boost::bimaps::relation::mutant_relation<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info,true>,boost::bimaps::detail::bimap_core<int,TString,boost::mpl::na,boost::mpl::na,boost::mpl::na>::core_indices,std::allocator<boost::bimaps::relation::mutant_relation<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info,true>>>::ctor_args_list>, 1> _Ty=boost::bimaps::relation::mutant_relation<boost::bimaps::tags::tagged<const int,boost::bimaps::relation::member_at::left>,boost::bimaps::tags::tagged<const std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>,boost::bimaps::relation::member_at::right>,boost::bimaps::detail::manage_additional_parameters<boost::mpl::na,boost::mpl::na,boost::mpl::na>::case_NNN::additional_info,true> 1> ] 1> c:\programming\programs\vc9\xxx\current\yyyyyyyyyy\zzzzzzzzzzzzzzzz.cpp(338) : see reference to function template instantiation 'boost::bimaps::bimap<KeyTypeA,KeyTypeB>::bimap<std::_Tree<_Traits>::iterator>(InputIterator,InputIterator)' being compiled 1> with 1> [ 1> KeyTypeA=int, 1> KeyTypeB=TString, 1> _Traits=std::_Tmap_traits<int,TString,std::less<int>,std::allocator<std::pair<const int,TString>>,false>, 1> InputIterator=std::_Tree<std::_Tmap_traits<int,TString,std::less<int>,std::allocator<std::pair<const int,TString>>,false>>::iterator 1> ]" So evidently that does not work. What is the problem with creating a bimap from the data in a std::map ? It seems as if it should be a no-braine and one of the chief selling points of using a bimap.