add to boost/libs/property_tree/examples/debug_settings.cpp: line 55 pt.equal_range("debug.level"); then compile: ~/boost/libs/property_tree/examples$ g++ -I../../../ debug_settings.cpp -o debug_settings ../../../boost/property_tree/detail/ptree_implementation.hpp: In member function ‘std::pair<typename boost::property_tree::basic_ptree<Key, Data, KeyCompare>::assoc_iterator, typename boost::property_tree::basic_ptree<Key, Data, KeyCompare>::assoc_iterator> boost::property_tree::basic_ptree<Key, Data, KeyCompare>::equal_range(const Key&) [with Key = std::basic_string<char, std::char_traits<char>, std::allocator<char>
, Data = std::basic_string<char, std::char_traits<char>, std::allocator<char> >, KeyCompare = std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >]’: debug_settings.cpp:55: instantiated from here ../../../boost/property_tree/detail/ptree_implementation.hpp:449: error: ‘class boost::multi_index::detail::bidir_node_iterator<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> , boost::property_tree::basic_ptree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> , std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::allocator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> , boost::property_tree::basic_ptree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> , std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > > > > >’ has no member named ‘base’ ../../../boost/property_tree/detail/ptree_implementation.hpp:449: error: ‘class boost::multi_index::detail::bidir_node_iterator<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> , boost::property_tree::basic_ptree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> , std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::allocator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> , boost::property_tree::basic_ptree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> , std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > > > > >’ has no member named ‘base’