Subject: [Boost-commit] svn:boost r73695 - trunk/boost/fusion/algorithm/transformation
From: joel_at_[hidden]
Date: 2011-08-12 07:43:26
Author: djowel
Date: 2011-08-12 07:43:24 EDT (Fri, 12 Aug 2011)
New Revision: 73695
URL: http://svn.boost.org/trac/boost/changeset/73695
Log:
Back on track. The code is fine again.
Text files modified:
trunk/boost/fusion/algorithm/transformation/pop_back.hpp | 96 +++++++++++++++++++++++++++++++++++-----
1 files changed, 84 insertions(+), 12 deletions(-)
Modified: trunk/boost/fusion/algorithm/transformation/pop_back.hpp
==============================================================================
--- trunk/boost/fusion/algorithm/transformation/pop_back.hpp (original)
+++ trunk/boost/fusion/algorithm/transformation/pop_back.hpp 2011-08-12 07:43:24 EDT (Fri, 12 Aug 2011)
@@ -1,7 +1,7 @@
/*=============================================================================
- Copyright (c) 2001-2006 Joel de Guzman
+ Copyright (c) 2001-2011 Joel de Guzman
- Distributed under the Boost Software License, Version 1.0. (See accompanying
+ 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_POP_BACK_09172005_1038)
@@ -10,22 +10,87 @@
#include <boost/fusion/view/iterator_range/iterator_range.hpp>
#include <boost/fusion/sequence/intrinsic/begin.hpp>
#include <boost/fusion/sequence/intrinsic/end.hpp>
-#include <boost/fusion/iterator/prior.hpp>
+#include <boost/fusion/sequence/intrinsic/empty.hpp>
+#include <boost/fusion/iterator/iterator_adapter.hpp>
+#include <boost/fusion/iterator/next.hpp>
+#include <boost/mpl/minus.hpp>
+#include <boost/mpl/int.hpp>
+#include <boost/mpl/if.hpp>
namespace boost { namespace fusion
{
+ template <typename Iterator_, bool IsLast>
+ struct pop_back_iterator
+ : iterator_adapter<
+ pop_back_iterator<Iterator_, IsLast>
+ , Iterator_>
+ {
+ typedef iterator_adapter<
+ pop_back_iterator<Iterator_, IsLast>
+ , Iterator_>
+ base_type;
+
+ static bool const is_last = IsLast;
+
+ pop_back_iterator(Iterator_ const& iterator_base)
+ : base_type(iterator_base) {}
+
+ template <bool P>
+ pop_back_iterator(pop_back_iterator<Iterator_, P> const& rhs)
+ : base_type(rhs.iterator_base) {}
+
+ template <typename BaseIterator>
+ struct make
+ {
+ typedef pop_back_iterator<BaseIterator, is_last> type;
+
+ static type
+ call(BaseIterator const& i)
+ {
+ return type(i);
+ }
+ };
+
+ template <typename I1, typename I2>
+ struct equal_to
+ : result_of::equal_to<
+ typename mpl::if_c<(I1::is_last|I2::is_last)
+ , typename result_of::next<
+ typename I1::iterator_base_type>::type
+ , typename I1::iterator_base_type>::type
+ , typename I2::iterator_base_type
+ >
+ {};
+
+ template <typename First, typename Last>
+ struct distance
+ : mpl::minus<
+ typename result_of::distance<
+ typename First::iterator_base_type
+ , typename Last::iterator_base_type
+ >::type
+ , mpl::int_<(Last::is_last?1:0)>
+ >::type
+ {};
+ };
+
namespace result_of
{
template <typename Sequence>
struct pop_back
{
- typedef
- iterator_range<
- typename begin<Sequence>::type
- , typename prior<
- typename end<Sequence>::type
- >::type
- >
+ BOOST_MPL_ASSERT_NOT((result_of::empty<Sequence>));
+
+ typedef pop_back_iterator<
+ typename begin<Sequence>::type, false>
+ begin_type;
+
+ typedef pop_back_iterator<
+ typename end<Sequence>::type, true>
+ end_type;
+
+ typedef
+ iterator_range<begin_type, end_type>
type;
};
}
@@ -34,8 +99,15 @@
inline typename result_of::pop_back<Sequence const>::type
pop_back(Sequence const& seq)
{
- typedef typename result_of::pop_back<Sequence const>::type result;
- return result(fusion::begin(seq), fusion::prior(fusion::end(seq)));
+ typedef result_of::pop_back<Sequence const> comp;
+ typedef typename comp::begin_type begin_type;
+ typedef typename comp::end_type end_type;
+ typedef typename comp::type result;
+
+ return result(
+ begin_type(fusion::begin(seq))
+ , end_type(fusion::end(seq))
+ );
}
}}