boost/mpl/zip_view.hpp

0001
0002 #ifndef BOOST_MPL_ZIP_VIEW_HPP_INCLUDED
0003 #define BOOST_MPL_ZIP_VIEW_HPP_INCLUDED
0004
0005 // Copyright Aleksey Gurtovoy 2000-2010
0006 // Copyright David Abrahams 2000-2002
0007 //
0008 // Distributed under the Boost Software License, Version 1.0.
0009 // (See accompanying file LICENSE_1_0.txt or copy at
0010 // http://www.boost.org/LICENSE_1_0.txt)
0011 //
0012 // See http://www.boost.org/libs/mpl for documentation.
0013
0014 // $Id$
0015 // $Date$
0016 // $Revision$
0017
0018 #include <boost/mpl/transform.hpp>
0019 #include <boost/mpl/begin_end.hpp>
0020 #include <boost/mpl/iterator_tags.hpp>
0021 #include <boost/mpl/next.hpp>
0022 #include <boost/mpl/lambda.hpp>
0023 #include <boost/mpl/deref.hpp>
0024 #include <boost/mpl/aux_/na_spec.hpp>
0025
0026 namespace boost { namespace mpl {
0027
0028 template< typename IteratorSeq >
0029 struct zip_iterator
0030 {
0031     typedef forward_iterator_tag category;
0032     typedef typename transform1<
0033           IteratorSeq
0034         , deref<_1>
0035         >::type type;
0036
0037     typedef zip_iterator<
0038           typename transform1<
0039                 IteratorSeq
0040               , mpl::next<_1>
0041             >::type
0042         > next;
0043 };
0044
0045 template<
0046       typename BOOST_MPL_AUX_NA_PARAM(Sequences)
0047     >
0048 struct zip_view
0049 {
0050  private:
0051     typedef typename transform1< Sequences, mpl::begin<_1> >::type first_ones_;
0052     typedef typename transform1< Sequences, mpl::end<_1> >::type last_ones_;
0053
0054  public:
0055     typedef nested_begin_end_tag tag;
0056     typedef zip_view type;
0057     typedef zip_iterator<first_ones_> begin;
0058     typedef zip_iterator<last_ones_> end;
0059 };
0060
0061 BOOST_MPL_AUX_NA_SPEC(1, zip_view)
0062
0063 }}
0064
0065 #endif // BOOST_MPL_ZIP_VIEW_HPP_INCLUDED