Re: [Boost-users] [multi-index] multi-index type trait

Elizabeta writes:

Hi how to test if the first index of boost::multi-index is key based or sequence based at compile time[...]

This can do: #include #include #include #include template<typename Index> struct is_key_based_index:boost::mpl::false_{}; template struct is_key_based_index< boost::multi_index::ordered_unique >:boost::mpl::true_{}; template struct is_key_based_index< boost::multi_index::ordered_non_unique >:boost::mpl::true_{}; template struct is_key_based_index< boost::multi_index::hashed_unique >:boost::mpl::true_{}; template struct is_key_based_index< boost::multi_index::hashed_non_unique >:boost::mpl::true_{}; template<typename MultiIndexContainer> struct is_first_index_key_based: is_key_based_index< typename boost::mpl::front< typename MultiIndexContainer::index_specifier_type_list >::type > {}; Full example at http://coliru.stacked-crooked.com/a/936add104162025d Joaquín M López Muñoz Telefónica