| |
| #ifndef BOOST_MPL_AUX_SINGLE_ELEMENT_ITER_HPP_INCLUDED |
| #define BOOST_MPL_AUX_SINGLE_ELEMENT_ITER_HPP_INCLUDED |
| |
| // Copyright Aleksey Gurtovoy 2000-2004 |
| // |
| // 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/mpl for documentation. |
| |
| // $Id: single_element_iter.hpp 49267 2008-10-11 06:19:02Z agurtovoy $ |
| // $Date: 2008-10-11 02:19:02 -0400 (Sat, 11 Oct 2008) $ |
| // $Revision: 49267 $ |
| |
| #include <boost/mpl/iterator_tags.hpp> |
| #include <boost/mpl/advance_fwd.hpp> |
| #include <boost/mpl/distance_fwd.hpp> |
| #include <boost/mpl/next_prior.hpp> |
| #include <boost/mpl/deref.hpp> |
| #include <boost/mpl/int.hpp> |
| #include <boost/mpl/aux_/nttp_decl.hpp> |
| #include <boost/mpl/aux_/value_wknd.hpp> |
| #include <boost/mpl/aux_/config/ctps.hpp> |
| |
| namespace boost { namespace mpl { |
| |
| #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) |
| |
| namespace aux { |
| |
| template< typename T, BOOST_MPL_AUX_NTTP_DECL(int, is_last_) > |
| struct sel_iter; |
| |
| template< typename T > |
| struct sel_iter<T,0> |
| { |
| typedef random_access_iterator_tag category; |
| typedef sel_iter<T,1> next; |
| typedef T type; |
| }; |
| |
| template< typename T > |
| struct sel_iter<T,1> |
| { |
| typedef random_access_iterator_tag category; |
| typedef sel_iter<T,0> prior; |
| }; |
| |
| } // namespace aux |
| |
| template< typename T, BOOST_MPL_AUX_NTTP_DECL(int, is_last_), typename Distance > |
| struct advance< aux::sel_iter<T,is_last_>,Distance> |
| { |
| typedef aux::sel_iter< |
| T |
| , ( is_last_ + BOOST_MPL_AUX_NESTED_VALUE_WKND(int, Distance) ) |
| > type; |
| }; |
| |
| template< |
| typename T |
| , BOOST_MPL_AUX_NTTP_DECL(int, l1) |
| , BOOST_MPL_AUX_NTTP_DECL(int, l2) |
| > |
| struct distance< aux::sel_iter<T,l1>, aux::sel_iter<T,l2> > |
| : int_<( l2 - l1 )> |
| { |
| }; |
| |
| #else |
| |
| namespace aux { |
| |
| struct sel_iter_tag; |
| |
| template< typename T, BOOST_MPL_AUX_NTTP_DECL(int, is_last_) > |
| struct sel_iter |
| { |
| enum { pos_ = is_last_ }; |
| typedef aux::sel_iter_tag tag; |
| typedef random_access_iterator_tag category; |
| |
| typedef sel_iter<T,(is_last_ + 1)> next; |
| typedef sel_iter<T,(is_last_ - 1)> prior; |
| typedef T type; |
| }; |
| |
| } // namespace aux |
| |
| template<> struct advance_impl<aux::sel_iter_tag> |
| { |
| template< typename Iterator, typename N > struct apply |
| { |
| enum { pos_ = Iterator::pos_, n_ = N::value }; |
| typedef aux::sel_iter< |
| typename Iterator::type |
| , (pos_ + n_) |
| > type; |
| }; |
| }; |
| |
| template<> struct distance_impl<aux::sel_iter_tag> |
| { |
| template< typename Iter1, typename Iter2 > struct apply |
| { |
| enum { pos1_ = Iter1::pos_, pos2_ = Iter2::pos_ }; |
| typedef int_<( pos2_ - pos1_ )> type; |
| BOOST_STATIC_CONSTANT(int, value = ( pos2_ - pos1_ )); |
| }; |
| }; |
| |
| #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION |
| |
| }} |
| |
| #endif // BOOST_MPL_AUX_SINGLE_ELEMENT_ITER_HPP_INCLUDED |