| /* Copyright 2003-2008 Joaquin M Lopez Munoz. |
| * Distributed under the Boost Software License, Version 1.0. |
| * (See accompanying file LICENSE_1_0.txt or copy at |
| * http://www.boost.org/LICENSE_1_0.txt) |
| * |
| * See http://www.boost.org/libs/multi_index for library home page. |
| */ |
| |
| #ifndef BOOST_MULTI_INDEX_DETAIL_NO_DUPLICATE_TAGS_HPP |
| #define BOOST_MULTI_INDEX_DETAIL_NO_DUPLICATE_TAGS_HPP |
| |
| #if defined(_MSC_VER)&&(_MSC_VER>=1200) |
| #pragma once |
| #endif |
| |
| #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */ |
| #include <boost/mpl/fold.hpp> |
| #include <boost/mpl/set/set0.hpp> |
| |
| namespace boost{ |
| |
| namespace multi_index{ |
| |
| namespace detail{ |
| |
| /* no_duplicate_tags check at compile-time that a tag list |
| * has no duplicate tags. |
| * The algorithm deserves some explanation: tags |
| * are sequentially inserted into a mpl::set if they were |
| * not already present. Due to the magic of mpl::set |
| * (mpl::has_key is contant time), this operation takes linear |
| * time, and even MSVC++ 6.5 handles it gracefully (other obvious |
| * solutions are quadratic.) |
| */ |
| |
| struct duplicate_tag_mark{}; |
| |
| struct duplicate_tag_marker |
| { |
| template <typename MplSet,typename Tag> |
| struct apply |
| { |
| typedef mpl::s_item< |
| typename mpl::if_<mpl::has_key<MplSet,Tag>,duplicate_tag_mark,Tag>::type, |
| MplSet |
| > type; |
| }; |
| }; |
| |
| template<typename TagList> |
| struct no_duplicate_tags |
| { |
| typedef typename mpl::fold< |
| TagList, |
| mpl::set0<>, |
| duplicate_tag_marker |
| >::type aux; |
| |
| BOOST_STATIC_CONSTANT( |
| bool,value=!(mpl::has_key<aux,duplicate_tag_mark>::value)); |
| }; |
| |
| /* Variant for an index list: duplication is checked |
| * across all the indices. |
| */ |
| |
| struct duplicate_tag_list_marker |
| { |
| template <typename MplSet,typename Index> |
| struct apply:mpl::fold< |
| BOOST_DEDUCED_TYPENAME Index::tag_list, |
| MplSet, |
| duplicate_tag_marker> |
| { |
| }; |
| }; |
| |
| template<typename IndexList> |
| struct no_duplicate_tags_in_index_list |
| { |
| typedef typename mpl::fold< |
| IndexList, |
| mpl::set0<>, |
| duplicate_tag_list_marker |
| >::type aux; |
| |
| BOOST_STATIC_CONSTANT( |
| bool,value=!(mpl::has_key<aux,duplicate_tag_mark>::value)); |
| }; |
| |
| } /* namespace multi_index::detail */ |
| |
| } /* namespace multi_index */ |
| |
| } /* namespace boost */ |
| |
| #endif |