[Boost-users] [multi_index] using boost::tuple and hash_unique

Hello, unfortunately I can't figure out how to specify member access for a hash function to a hash indexed mult-index container containing boost::tuple. I would like to hash by the first tuple member only. Can someone help? Here is an example: typedef boost::tuples::tuple my_tuple; struct hash {}; multi_index_container< my_tuple , indexed_by< hashed_unique

hashed_container;

I would like this tuple to be hashed by the first member. boost::tuple has no access member function to the first member. The only way to access it is: my_tuple t("aaa", 10, xyz); std::string s(get<0>(t)); but as I can see the doc for multi_index it supports only access through a member function or by using the hash function which is applied to the whole object. The second scenario does not suit well, since I must pass an object instance to the hasher, where I would like to pass a name only. Should I write my own key_extractor class? Any help is appreciated. With Kind Regards, Ovanes