I am trying to use Boost.Multi-index (version 1.33.0) to store a set of boost::tuples, and it appears that const_mem_fun has some difficulties when the desired member function is inherited from a base class. The following typedef typedef multi_index_container< tuple<int>, indexed_by< ordered_non_unique< const_mem_fun< tuple<int>, const int&, &tuple<int>::get<0> > > >

my_tuple_container_type;

yields this error (edited for clarity) on my compiler (g++ 4.0.3): &TupleBaseClass<int>::get' is not a valid template argument for type 'const int& (tuple<int>::*)()const' because it is of type 'const int& (TupleBaseClass<int>::*)const' note: standard conversions are not allowed in this context Now the declaration of boost::tuple has something like this: template <class T> class tuple : public TupleBaseClass<T> { public: typedef typename TupleBaseClass<T> inherited; ... }; (Also, as far as I can tell, get<0>() is declared and implemented in TupleBaseClass, not tuple). The public typedef 'inherited' looked promising, so I modified my code as follows: typedef multi_index_container< tuple<int>, indexed_by< ordered_non_unique< const_mem_fun< tuple<int>::inherited, const int&, &tuple<int>::get<0> > > >

my_tuple_container_type;

and that compiles. I have a few questions/comments about all this. First of all, is my compiler correct to generate the error for the first case? Secondly, is the above workaround satisfactory? My opinion is that it's a little ungainly; it appears to me that boost::tuple is a derived type for implementation reasons, and I'd rather not have to know about that fact. Thank you. Matt Steele