2 #ifndef BOOST_MPL_AUX_SINGLE_ELEMENT_ITER_HPP_INCLUDED
3 #define BOOST_MPL_AUX_SINGLE_ELEMENT_ITER_HPP_INCLUDED
5 // Copyright Aleksey Gurtovoy 2000-2004
7 // Distributed under the Boost Software License, Version 1.0.
8 // (See accompanying file LICENSE_1_0.txt or copy at
9 // http://www.boost.org/LICENSE_1_0.txt)
11 // See http://www.boost.org/libs/mpl for documentation.
17 #include <boost/mpl/iterator_tags.hpp>
18 #include <boost/mpl/advance_fwd.hpp>
19 #include <boost/mpl/distance_fwd.hpp>
20 #include <boost/mpl/next_prior.hpp>
21 #include <boost/mpl/deref.hpp>
22 #include <boost/mpl/int.hpp>
23 #include <boost/mpl/aux_/nttp_decl.hpp>
24 #include <boost/mpl/aux_/value_wknd.hpp>
25 #include <boost/mpl/aux_/config/ctps.hpp>
27 namespace boost { namespace mpl {
29 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
33 template< typename T, BOOST_MPL_AUX_NTTP_DECL(int, is_last_) >
36 template< typename T >
39 typedef random_access_iterator_tag category;
40 typedef sel_iter<T,1> next;
44 template< typename T >
47 typedef random_access_iterator_tag category;
48 typedef sel_iter<T,0> prior;
53 template< typename T, BOOST_MPL_AUX_NTTP_DECL(int, is_last_), typename Distance >
54 struct advance< aux::sel_iter<T,is_last_>,Distance>
56 typedef aux::sel_iter<
58 , ( is_last_ + BOOST_MPL_AUX_NESTED_VALUE_WKND(int, Distance) )
64 , BOOST_MPL_AUX_NTTP_DECL(int, l1)
65 , BOOST_MPL_AUX_NTTP_DECL(int, l2)
67 struct distance< aux::sel_iter<T,l1>, aux::sel_iter<T,l2> >
78 template< typename T, BOOST_MPL_AUX_NTTP_DECL(int, is_last_) >
81 enum { pos_ = is_last_ };
82 typedef aux::sel_iter_tag tag;
83 typedef random_access_iterator_tag category;
85 typedef sel_iter<T,(is_last_ + 1)> next;
86 typedef sel_iter<T,(is_last_ - 1)> prior;
92 template<> struct advance_impl<aux::sel_iter_tag>
94 template< typename Iterator, typename N > struct apply
96 enum { pos_ = Iterator::pos_, n_ = N::value };
97 typedef aux::sel_iter<
98 typename Iterator::type
104 template<> struct distance_impl<aux::sel_iter_tag>
106 template< typename Iter1, typename Iter2 > struct apply
108 enum { pos1_ = Iter1::pos_, pos2_ = Iter2::pos_ };
109 typedef int_<( pos2_ - pos1_ )> type;
110 BOOST_STATIC_CONSTANT(int, value = ( pos2_ - pos1_ ));
114 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
118 #endif // BOOST_MPL_AUX_SINGLE_ELEMENT_ITER_HPP_INCLUDED