A doubt in Boost multi index

Gokulakannan Somasundaram

30 Jul 2010 30 Jul '10

10:21 a.m.

Hi, In boost multi-index, can i verify whether a particular index type is ordered/not or not through meta programming? There are the ordered indexes, hash indexes, sequence indexes etc. Can i find them out through meta programming? Thanks, Gokul.

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joaquin＠tid.es

30 Jul 30 Jul

11:49 a.m.

Gokulakannan Somasundaram escribió:

...

Hi, In boost multi-index, can i verify whether a particular index type is ordered/not or not through meta programming? There are the ordered indexes, hash indexes, sequence indexes etc. Can i find them out through meta programming?

You can if you're given the multi_index_containr type and the position of the index: #include #include #include template<typename IndexSpecifier> struct is_ordered_index_impl:boost::mpl::false_{}; template struct is_ordered_index_impl< boost::multi_index::ordered_unique

...

:boost::mpl::true_{};

template struct is_ordered_index_impl< boost::multi_index::ordered_non_unique

...

:boost::mpl::true_{};

template struct is_ordered_index: is_ordered_index_impl< typename boost::mpl::at_c< typename MultiIndexContainer::index_specifier_type_list, N >::type > {}; /* testing */ #include #include #include #include #include using namespace boost::multi_index; typedef multi_index_container< int, indexed_by< ordered_unique, ordered_non_unique, hashed_unique, hashed_non_unique, sequenced<> >

...

multi_t;

Gokulakannan Somasundaram

12:03 p.m.

On Fri, Jul 30, 2010 at 7:49 PM, wrote:

...

Gokulakannan Somasundaram escribió:

Hi,

...
In boost multi-index, can i verify whether a particular index type is ordered/not or not through meta programming? There are the ordered indexes, hash indexes, sequence indexes etc. Can i find them out through meta programming?

You can if you're given the multi_index_containr type and the position of the index:

Thanks a lot. Is it possible to do the same with named tags? Thanks, Gokul.

joaquin＠tid.es

12:35 p.m.

Gokulakannan Somasundaram escribió:

...

On Fri, Jul 30, 2010 at 7:49 PM, mailto:joaquin@tid.es> wrote:

Gokulakannan Somasundaram escribió:

Hi, In boost multi-index, can i verify whether a particular index type is ordered/not or not through meta programming? There are the ordered indexes, hash indexes, sequence indexes etc. Can i find them out through meta programming?

You can if you're given the multi_index_containr type and the position of the index:

Thanks a lot. Is it possible to do the same with named tags?

With a little more effort: #include #include #include template<typename IndexSpecifier> struct is_ordered_index_impl:boost::mpl::false_{}; template struct is_ordered_index_impl< boost::multi_index::ordered_unique

...

:boost::mpl::true_{};

template struct is_ordered_index_impl< boost::multi_index::ordered_non_unique

...

:boost::mpl::true_{};

template struct is_ordered_index: is_ordered_index_impl< typename boost::mpl::at_c< typename MultiIndexContainer::index_specifier_type_list, N >::type > {}; #include #include #include #include template<typename Index> struct tag_list { typedef typename Index::tag_list type; }; template struct tag_pos: boost::mpl::distance< typename boost::mpl::begin<IndexList>::type, typename boost::mpl::find_if< IndexList, boost::mpl::containsboost::mpl::_,Tag> >::type > {}; template struct is_ordered_index_with_tag: is_ordered_index< MultiIndexContainer, tag_pos::value > {}; /* testing */ #include #include #include #include #include using namespace boost::multi_index; typedef multi_index_container< int, indexed_by< ordered_unique, ordered_non_unique, hashed_unique, hashed_non_unique, sequenced >

...

multi_t;

BOOST_MPL_ASSERT ((is_ordered_index)); BOOST_MPL_ASSERT ((is_ordered_index)); BOOST_MPL_ASSERT_NOT((is_ordered_index)); BOOST_MPL_ASSERT_NOT((is_ordered_index)); BOOST_MPL_ASSERT_NOT((is_ordered_index)); BOOST_MPL_ASSERT ((is_ordered_index_with_tag)); BOOST_MPL_ASSERT ((is_ordered_index_with_tag)); BOOST_MPL_ASSERT_NOT((is_ordered_index_with_tag)); BOOST_MPL_ASSERT_NOT((is_ordered_index_with_tag)); BOOST_MPL_ASSERT_NOT((is_ordered_index_with_tag)); int main(){} Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

Gokulakannan Somasundaram

1:24 p.m.

Thanks a lot. I could make sense of your first one with some difficulty. I am trying to understand the next one. Anyways, i will just use it as template to solve my problem. Thanks, Gokul. On Fri, Jul 30, 2010 at 8:35 PM, wrote:

...

Gokulakannan Somasundaram escribió:

...
On Fri, Jul 30, 2010 at 7:49 PM, mailto:joaquin@tid.es> wrote:

Gokulakannan Somasundaram escribió:

Hi, In boost multi-index, can i verify whether a particular index type is ordered/not or not through meta programming? There are the ordered indexes, hash indexes, sequence indexes etc. Can i find them out through meta programming?

You can if you're given the multi_index_containr type and the position of the index:

Thanks a lot. Is it possible to do the same with named tags?

With a little more effort:

#include #include #include

template<typename IndexSpecifier> struct is_ordered_index_impl:boost::mpl::false_{};

template struct is_ordered_index_impl< boost::multi_index::ordered_unique

...
:boost::mpl::true_{};

template struct is_ordered_index_impl< boost::multi_index::ordered_non_unique

...
:boost::mpl::true_{};

template struct is_ordered_index: is_ordered_index_impl< typename boost::mpl::at_c< typename MultiIndexContainer::index_specifier_type_list, N >::type

...
{};

#include #include #include #include

template<typename Index> struct tag_list { typedef typename Index::tag_list type; };

template struct tag_pos: boost::mpl::distance< typename boost::mpl::begin<IndexList>::type, typename boost::mpl::find_if< IndexList, boost::mpl::containsboost::mpl::_,Tag> >::type

...
{};

template struct is_ordered_index_with_tag: is_ordered_index< MultiIndexContainer, tag_pos::value

...
{};

/* testing */

#include #include #include #include #include

using namespace boost::multi_index;

typedef multi_index_container< int, indexed_by< ordered_unique, ordered_non_unique, hashed_unique, hashed_non_unique, sequenced

...
multi_t;

BOOST_MPL_ASSERT ((is_ordered_index)); BOOST_MPL_ASSERT ((is_ordered_index)); BOOST_MPL_ASSERT_NOT((is_ordered_index)); BOOST_MPL_ASSERT_NOT((is_ordered_index)); BOOST_MPL_ASSERT_NOT((is_ordered_index));

BOOST_MPL_ASSERT ((is_ordered_index_with_tag)); BOOST_MPL_ASSERT ((is_ordered_index_with_tag)); BOOST_MPL_ASSERT_NOT((is_ordered_index_with_tag)); BOOST_MPL_ASSERT_NOT((is_ordered_index_with_tag)); BOOST_MPL_ASSERT_NOT((is_ordered_index_with_tag));

int main(){}

Joaquín M López Muñoz Telefónica, Investigación y Desarrollo _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Gokulakannan Somasundaram
joaquin＠tid.es