Index: boost/mpl/equal.hpp
===================================================================
--- boost/mpl/equal.hpp	(revision 53096)
+++ boost/mpl/equal.hpp	(working copy)
@@ -74,8 +74,7 @@
         , first2_
         , next<>
         , protect< aux::equal_pred<Predicate,last1_,last2_> >
-        , void_
-        , always<false_>
+        , identity<>
         > fold_;
 
     typedef typename fold_::iterator iter1_;
Index: boost/mpl/aux_/iter_fold_if_impl.hpp
===================================================================
--- boost/mpl/aux_/iter_fold_if_impl.hpp	(revision 53096)
+++ boost/mpl/aux_/iter_fold_if_impl.hpp	(working copy)
@@ -81,6 +81,34 @@
     };
 };
 
+template< bool >
+struct iter_fold_if_backward_step_impl
+{
+    template<
+          typename Iterator
+        , typename State
+        , typename StateOp
+        >
+    struct result_
+    {
+        typedef typename apply2<StateOp,State,Iterator>::type state;
+    };
+};
+
+template<>
+struct iter_fold_if_backward_step_impl<false>
+{
+    template<
+          typename Iterator
+        , typename State
+        , typename StateOp
+        >
+    struct result_
+    {
+        typedef State state;
+    };
+};
+
 // agurt, 25/jun/02: MSVC 6.5 workaround, had to get rid of inheritance 
 // here and in 'iter_fold_if_backward_step', because sometimes it interfered 
 // with the "early template instantiation bug" in _really_ ugly ways
@@ -104,18 +132,16 @@
 template<
       typename Iterator
     , typename State
+    , typename ForwardNotLast
     , typename BackwardOp
-    , typename Predicate
     >
 struct iter_fold_if_backward_step
 {
-    typedef typename apply2<Predicate,State,Iterator>::type not_last;
-    typedef typename iter_fold_if_step_impl<
-          BOOST_MPL_AUX_MSVC_VALUE_WKND(not_last)::value
-        >::template result_< Iterator,State,BackwardOp,identity<Iterator> > impl_;
+    typedef typename iter_fold_if_backward_step_impl<
+          BOOST_MPL_AUX_MSVC_VALUE_WKND(ForwardNotLast)::value
+        >::template result_< Iterator,State,BackwardOp> impl_;
 
     typedef typename impl_::state state;
-    typedef typename impl_::iterator iterator;
 };
 
 
@@ -134,8 +160,8 @@
     typedef iter_fold_if_backward_step< \
           typename BOOST_PP_CAT(forward_step,BOOST_PP_DEC(i))::iterator \
         , typename BOOST_PP_CAT(backward_step,i)::state \
+        , typename BOOST_PP_CAT(forward_step,i)::not_last \
         , BackwardOp \
-        , BackwardPredicate \
         > BOOST_PP_CAT(backward_step,BOOST_PP_DEC(i)); \
     /**/
 
@@ -159,7 +185,6 @@
     , typename ForwardOp
     , typename ForwardPredicate
     , typename BackwardOp
-    , typename BackwardPredicate
     >
 struct iter_fold_if_impl
 {
@@ -179,7 +204,6 @@
             , ForwardOp
             , ForwardPredicate
             , BackwardOp
-            , BackwardPredicate
             >
         , iter_fold_if_null_step<
               typename AUX_LAST_FORWARD_STEP::iterator
Index: boost/mpl/iter_fold_if.hpp
===================================================================
--- boost/mpl/iter_fold_if.hpp	(revision 53096)
+++ boost/mpl/iter_fold_if.hpp	(working copy)
@@ -62,7 +62,6 @@
     , typename BOOST_MPL_AUX_NA_PARAM(ForwardOp)
     , typename BOOST_MPL_AUX_NA_PARAM(ForwardPredicate)
     , typename BOOST_MPL_AUX_NA_PARAM(BackwardOp)
-    , typename BOOST_MPL_AUX_NA_PARAM(BackwardPredicate)
     >
 struct iter_fold_if
 {
@@ -70,11 +69,7 @@
     typedef typename begin<Sequence>::type first_;
     typedef typename end<Sequence>::type last_;
 
-    typedef typename eval_if<
-          is_na<BackwardPredicate>
-        , if_< is_na<BackwardOp>, always<false_>, always<true_> >
-        , identity<BackwardPredicate>
-        >::type backward_pred_;
+    typedef typename if_< is_na<BackwardOp>, identity<>, BackwardOp >::type backward_op_;
 
 // cwpro8 doesn't like 'cut-off' type here (use typedef instead)
 #if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003)) && !BOOST_WORKAROUND(__IBMCPP__, BOOST_TESTED_AT(600))
@@ -87,8 +82,7 @@
         , State
         , ForwardOp
         , protect< aux::iter_fold_if_pred< ForwardPredicate,last_ > >
-        , BackwardOp
-        , backward_pred_
+        , backward_op_
         >
 #if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003)) && !BOOST_WORKAROUND(__IBMCPP__, BOOST_TESTED_AT(600))
     { };
@@ -104,13 +98,13 @@
         > type;
 
     BOOST_MPL_AUX_LAMBDA_SUPPORT(
-          6
+          5
         , iter_fold_if
-        , (Sequence,State,ForwardOp,ForwardPredicate,BackwardOp,BackwardPredicate)
+        , (Sequence,State,ForwardOp,ForwardPredicate,BackwardOp)
         )
 };
 
-BOOST_MPL_AUX_NA_SPEC(6, iter_fold_if)
+BOOST_MPL_AUX_NA_SPEC(5, iter_fold_if)
 
 }}
 
Index: libs/mpl/test/iter_fold_if.cpp
===================================================================
--- libs/mpl/test/iter_fold_if.cpp	(revision 0)
+++ libs/mpl/test/iter_fold_if.cpp	(revision 0)
@@ -0,0 +1,72 @@
+
+// Copyright Steven Watanabe 2009
+//
+// 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.
+
+// $Id$
+// $Date: $
+// $Revision: $
+
+#include <boost/mpl/iter_fold_if.hpp>
+
+#include <boost/mpl/list.hpp>
+#include <boost/mpl/list_c.hpp>
+#include <boost/mpl/end.hpp>
+#include <boost/mpl/advance.hpp>
+#include <boost/mpl/always.hpp>
+#include <boost/mpl/equal_to.hpp>
+#include <boost/mpl/not_equal_to.hpp>
+#include <boost/mpl/plus.hpp>
+#include <boost/mpl/bool.hpp>
+#include <boost/mpl/int.hpp>
+
+#include <boost/mpl/aux_/test.hpp>
+
+MPL_TEST_CASE()
+{
+    typedef iter_fold_if<list<>, void, deref<_2>, always<true_>, deref<_2> >::type result;
+    MPL_ASSERT((is_same<result::first, void>));
+}
+
+MPL_TEST_CASE() // test forward fold functionality
+{
+    typedef list<char, short, int, long, float, double> types;
+    typedef iter_fold_if<types, void, deref<_2>, always<true_> >::type result;
+    MPL_ASSERT((is_same<result::first, double>));
+    MPL_ASSERT((is_same<result::second, end<types>::type>));
+}
+
+MPL_TEST_CASE() // test reverse fold functionality
+{
+    typedef list<char, short, int, long, float, double> types;
+    typedef iter_fold_if<types, void, deref<_2>, always<true_>, deref<_2> >::type result;
+    MPL_ASSERT((is_same<result::first, char>));
+    MPL_ASSERT((is_same<result::second, end<types>::type>));
+}
+
+MPL_TEST_CASE() // test forward condition
+{
+    typedef list_c<int, 1, 2, 4, 8, 16> numbers;
+    typedef iter_fold_if<numbers, int_<0>, plus<_1, deref<_2> >, not_equal_to<deref<_1>, int_<8> > >::type result;
+    MPL_ASSERT((equal_to<result::first, int_<7> >));
+    MPL_ASSERT((is_same<result::second, advance_c<begin<numbers>::type, 3>::type>));
+}
+
+
+MPL_TEST_CASE() // test backwards condition
+{
+    typedef list_c<int, 1, 2, 4, 8, 16> numbers;
+    typedef iter_fold_if<
+        numbers
+      , int_<0>
+      , identity<_1>
+      , not_equal_to<deref<_1>, int_<8> >
+      , plus<_1, deref<_2> >
+      >::type result;
+    MPL_ASSERT((equal_to<result::first, int_<7> >));
+    MPL_ASSERT((is_same<result::second, advance_c<begin<numbers>::type, 3>::type>));
+}

Property changes on: libs\mpl\test\iter_fold_if.cpp
___________________________________________________________________
Name: svn:mime-type
   + text/plain
Name: svn:keywords
   + Id
Name: svn:eol-style
   + native

Index: libs/mpl/test/Jamfile.v2
===================================================================
--- libs/mpl/test/Jamfile.v2	(revision 53096)
+++ libs/mpl/test/Jamfile.v2	(working copy)
@@ -49,6 +49,7 @@
 compile is_placeholder.cpp ;
 compile is_sequence.cpp ;
 compile iterator_tags.cpp ;
+compile iter_fold_if.cpp ;
 compile joint_view.cpp ;
 compile lambda.cpp ;
 compile lambda_args.cpp ;