[Boost-users] multi_index and base class

Hi, I'm trying to store these classes in a multi_index: struct Foo { int a; }; struct Bar :Foo { }; typedef multi_index_container< Bar, indexed_by< ordered_unique< member > >

Bar_container;

Notice I have to use "Foo" in the "member<" line. However, even with this, when trying to do a search: Bar_container bar_container; int function() { Bar_container::nth_index<0>::type& a_index = bar_container.get<0>(); Bar_container::nth_index<0>::type::iterator i = a_index.find(5); if (i != a_index.end()) return -1; return 0; } I get this: /usr/include/boost/multi_index/member.hpp: In member function 'Type& boost::multi_index::detail::non_const_member_base::operator()(const ChainedPtr&) const [with ChainedPtr = Bar, Class = Foo, Type = int, Type Class::* PtrToMember = &Foo::a]': /usr/include/boost/multi_index/detail/ord_index_ops.hpp:65: instantiated from 'Node* boost::multi_index::detail::ordered_index_find(Node*, const KeyFromValue&, const CompatibleKey&, const CompatibleCompare&) [with Node = boost::multi_index::detail::ordered_index_node

, KeyFromValue = boost::multi_index::member, CompatibleKey = int, CompatibleCompare = std::less<int>]' /usr/include/boost/multi_index/ordered_index.hpp:376: instantiated from 'boost::multi_index::detail::index_iterator boost::multi_index::detail::ordered_index::find(const CompatibleKey&) const [with CompatibleKey = int, KeyFromValue = boost::multi_index::member, Compare = std::less<int>, SuperMeta = boost::multi_index::detail::nth_layer<1, Bar, boost::multi_index::indexed_by, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, std::allocator<Bar> >, TagList = boost::mpl::vector0, Category = boost::multi_index::detail::ordered_unique_tag]' multitest2.cc:55: instantiated from here /usr/include/boost/multi_index/member.hpp:84: error: no match for 'operator*' in '*x'

I've tried a few alternatives such as providing a custom compare function but I always get this error. It seems to have something to do with the fact that the key is in the base class. If I move the key to the derived class (and change the "member<" line), it works fine. Surely there's a way to do this. Anyone know how ? Using gcc version 4.1.2 20061115 (prerelease) (Debian 4.1.1-21) and libboost 1.33.1. Thanks ___________________________________________________________ New Yahoo! Mail is the ultimate force in competitive emailing. Find out more at the Yahoo! Mail Championships. Plus: play games and win prizes. http://uk.rd.yahoo.com/evt=44106/*http://mail.yahoo.net/uk