I am looking for a container where I have to use 5-10 keys to get the value.

I am trying to write something like below.. Can some one help to solve this?

struct entry

{

    int a[10];

    int id;

};

using boost::multi_index_container;

using namespace boost::multi_index;

typedef multi_index_container<

    entry,

    indexed_by<

    ordered_non_unique< 

    composite_key<

    entry,

    member<entry,unsigned int,&entry::a> ????

    >

    >,

    ordered_unique< 

    member<entry,unsigned int,&entry::id>

    >

    >

> book;

Regards,

UJ