25 Jul
2013
25 Jul
'13
11:24 a.m.
Hello, The following code is expected to get the key-extractor, but it doesn't compile. How to do this correctly? Thanks. #include <boost/multi_index_container.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/mem_fun.hpp> struct A { int f() const { return 0; } }; typedef boost::multi_index::multi_index_container< int, boost::multi_index::indexed_by< boost::multi_index::ordered_unique< boost::multi_index::const_mem_fun<A, int, &A::f> > >
container_type;
typedef container_type::key_from_value_type extractor_type; // doesn't compile typedef container_type::nth_index<0>::key_from_value_type extractor_type; // doesn't compile