I am having below composite container. I am looking to sort the container by member<CA,std::string,&CA::card> at the end.

Can some one help me to achieve this?

typedef multi_index_container<

  CA,

  indexed_by<

    ordered_unique<

      composite_key<

        CA,

        member<CA,std::string,&CA::name>,

        member<CA,std::string,&CA::displayName>,

        member<CA,std::string,&CA::card>

      >

    >

  >

> duplicateBook;