/* 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 |