WSJT-X/boost/fusion/adapted/std_tuple/std_tuple_iterator.hpp
Bill Somerville 4ebe6417a5 Squashed 'boost/' content from commit b4feb19f2
git-subtree-dir: boost
git-subtree-split: b4feb19f287ee92d87a9624b5d36b7cf46aeadeb
2018-06-09 21:48:32 +01:00

122 lines
3.6 KiB
C++

/*=============================================================================
Copyright (c) 2001-2011 Joel de Guzman
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)
==============================================================================*/
#if !defined(FUSION_STD_TUPLE_ITERATOR_09112011_1905)
#define FUSION_STD_TUPLE_ITERATOR_09112011_1905
#include <boost/fusion/support/config.hpp>
#include <boost/fusion/iterator/iterator_facade.hpp>
#include <boost/type_traits/is_const.hpp>
#include <boost/type_traits/remove_const.hpp>
#include <boost/fusion/support/detail/access.hpp>
#include <boost/mpl/int.hpp>
#include <boost/mpl/if.hpp>
#include <tuple>
#include <utility>
namespace boost { namespace fusion
{
struct random_access_traversal_tag;
template <typename Tuple, int Index>
struct std_tuple_iterator_identity;
template <typename Tuple, int Index>
struct std_tuple_iterator
: iterator_facade<
std_tuple_iterator<Tuple, Index>
, random_access_traversal_tag>
{
typedef Tuple tuple_type;
static int const index = Index;
typedef std_tuple_iterator_identity<
typename add_const<Tuple>::type, Index>
identity;
BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
explicit std_tuple_iterator(Tuple& tuple)
: tuple(tuple) {}
Tuple& tuple;
template <typename Iterator>
struct value_of
: std::tuple_element<Iterator::index,
typename remove_const<typename Iterator::tuple_type>::type> {};
template <typename Iterator>
struct deref
{
typedef typename value_of<Iterator>::type element;
typedef typename
mpl::if_<
is_const<typename Iterator::tuple_type>
, typename fusion::detail::cref_result<element>::type
, typename fusion::detail::ref_result<element>::type
>::type
type;
BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
static type
call(Iterator const& iter)
{
return std::get<Index>(iter.tuple);
}
};
template <typename Iterator, typename N>
struct advance
{
static int const index = Iterator::index;
typedef typename Iterator::tuple_type tuple_type;
typedef std_tuple_iterator<tuple_type, index+N::value> type;
BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
static type
call(Iterator const& i)
{
return type(i.tuple);
}
};
template <typename Iterator>
struct next : advance<Iterator, mpl::int_<1>> {};
template <typename Iterator>
struct prior : advance<Iterator, mpl::int_<-1>> {};
template <typename I1, typename I2>
struct equal_to
: is_same<typename I1::identity, typename I2::identity> {};
template <typename First, typename Last>
struct distance
{
typedef mpl::int_<Last::index-First::index> type;
BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
static type
call(First const&, Last const&)
{
return type();
}
};
};
}}
#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
namespace std
{
template <typename Tuple, int Index>
struct iterator_traits< ::boost::fusion::std_tuple_iterator<Tuple, Index> >
{ };
}
#endif
#endif