diff --git a/include/boost/mpl/aux_/find_if_pred.hpp b/include/boost/mpl/aux_/find_if_pred.hpp
index 4bf5348..ebac68c 100644
--- a/include/boost/mpl/aux_/find_if_pred.hpp
+++ b/include/boost/mpl/aux_/find_if_pred.hpp
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2000-02
-// Aleksey Gurtovoy
+// Aleksey Gurtovoy, Eric Friedman
 //
 // Permission to use, copy, modify, distribute and sell this software
 // and its documentation for any purpose is hereby granted without fee, 
@@ -18,25 +18,19 @@
 #define BOOST_MPL_AUX_FIND_IF_PRED_HPP_INCLUDED
 
 #include "boost/mpl/aux_/iter_apply.hpp"
-#include "boost/mpl/apply.hpp"
 #include "boost/mpl/not.hpp"
-#include "boost/mpl/or.hpp"
-#include "boost/type_traits/is_same.hpp"
 
 namespace boost {
 namespace mpl {
 namespace aux {
 
-template< typename Predicate, typename LastIterator >
+template< typename Predicate >
 struct find_if_pred
 {
-    template< typename State, typename Iterator >
+    template< typename Iterator >
     struct apply
     {
-        typedef not_< or_<
-              is_same<Iterator,LastIterator>
-            , aux::iter_apply1<Predicate,Iterator>
-            > > type;
+        typedef not_< aux::iter_apply1<Predicate,Iterator> > type;
     };
 };
 
diff --git a/include/boost/mpl/find_if.hpp b/include/boost/mpl/find_if.hpp
index ea2fbae..3f3f5ca 100644
--- a/include/boost/mpl/find_if.hpp
+++ b/include/boost/mpl/find_if.hpp
@@ -18,36 +18,16 @@
 #define BOOST_MPL_FIND_IF_HPP_INCLUDED
 
 #include "boost/mpl/aux_/find_if_pred.hpp"
-#include "boost/mpl/aux_/iter_fold_if_impl.hpp"
-#include "boost/mpl/begin_end.hpp"
-#include "boost/mpl/always.hpp"
+#include "boost/mpl/arg.hpp"
 #include "boost/mpl/lambda.hpp"
+#include "boost/mpl/iter_fold_if.hpp"
+#include "boost/mpl/protect.hpp"
 #include "boost/mpl/aux_/void_spec.hpp"
 #include "boost/mpl/aux_/lambda_support.hpp"
 
 namespace boost {
 namespace mpl {
 
-namespace aux {
-/*
-template< typename LastIterator >
-struct find_if_pred
-{
-    template<
-          typename Predicate
-        , typename Iterator
-        >
-    struct apply
-    {
-        typedef typename not_< or_<
-              is_same<Iterator,LastIterator>
-            , aux::iter_apply1<Predicate,Iterator>
-            > >::type type;
-    };
-};
-*/
-} // namespace aux
-
 BOOST_MPL_AUX_AGLORITHM_NAMESPACE_BEGIN
 
 template<
@@ -56,22 +36,23 @@ template<
     >
 struct find_if
 {
- private:
-    typedef typename begin<Sequence>::type first_;
-    typedef typename end<Sequence>::type last_;
+private:
+
     typedef typename lambda<Predicate>::type pred_;
 
- public:
-    typedef typename aux::iter_fold_if_impl<
-          first_
+    typedef typename iter_fold_if<
+          Sequence
         , void
-        , mpl::arg<1>
-        , aux::find_if_pred< pred_, last_ >
-        , void
-        , always<false_>
-        >::iterator type;
+        , protect< arg<1> > // ignore
+        , protect< aux::find_if_pred<pred_> >
+        >::type result_;
+
+public:
+
+    typedef typename result_::second type;
 
     BOOST_MPL_AUX_LAMBDA_SUPPORT(2,find_if,(Sequence,Predicate))
+
 };
 
 BOOST_MPL_AUX_AGLORITHM_NAMESPACE_END
diff --git a/include/boost/mpl/index_if.hpp b/include/boost/mpl/index_if.hpp
index 2740788..ead1b6b 100644
--- a/include/boost/mpl/index_if.hpp
+++ b/include/boost/mpl/index_if.hpp
@@ -57,29 +57,29 @@ struct index_if
 {
 private:
 
-    typedef typename begin<Sequence>::type first_;
-    typedef typename end<Sequence>::type last_;
     typedef typename lambda<Predicate>::type pred_;
 
     typedef typename iter_fold_if<
-          first_
+          Sequence
         , int_<0>
         , protect< aux::index_if_op >
-        , protect< aux::find_if_pred<pred_,last_> >
+        , protect< aux::find_if_pred<pred_> >
         >::type result_;
 
+    typedef typename end<Sequence>::type not_found_;
     typedef typename result_::first result_index_;
     typedef typename result_::second result_iterator_;
 
 public:
 
     typedef typename if_<
-          is_same< result_iterator_,last_ >
+          is_same< result_iterator_,not_found_ >
         , void_
         , result_index_
         >::type type;
 
     BOOST_MPL_AUX_LAMBDA_SUPPORT(2,index_if,(Sequence,Predicate))
+
 };
 
 BOOST_MPL_AUX_AGLORITHM_NAMESPACE_END
diff --git a/include/boost/mpl/iter_fold_if.hpp b/include/boost/mpl/iter_fold_if.hpp
index 3c2a332..02aabf6 100644
--- a/include/boost/mpl/iter_fold_if.hpp
+++ b/include/boost/mpl/iter_fold_if.hpp
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2003
-// Eric Friedman
+// Eric Friedman, Aleksey Gurtovoy
 //
 // Permission to use, copy, modify, distribute and sell this software
 // and its documentation for any purpose is hereby granted without fee, 
@@ -18,29 +18,65 @@
 #define BOOST_MPL_ITER_FOLD_IF_HPP_INCLUDED
 
 #include "boost/mpl/aux_/iter_fold_if_impl.hpp"
+#include "boost/mpl/and.hpp"
 #include "boost/mpl/always.hpp"
+#include "boost/mpl/apply.hpp"
+#include "boost/mpl/apply_if.hpp"
+#include "boost/mpl/begin_end.hpp"
 #include "boost/mpl/bool.hpp"
+#include "boost/mpl/if.hpp"
 #include "boost/mpl/lambda.hpp"
+#include "boost/mpl/not.hpp"
 #include "boost/mpl/pair.hpp"
 #include "boost/mpl/void.hpp"
 #include "boost/mpl/aux_/void_spec.hpp"
 #include "boost/mpl/aux_/lambda_support.hpp"
+#include "boost/type_traits/is_same.hpp"
 
 namespace boost {
 namespace mpl {
 
+namespace aux {
+
+template< typename Predicate, typename LastIterator >
+struct iter_fold_if_pred
+{
+    template< typename State, typename Iterator >
+    struct apply
+    {
+        typedef and_<
+              not_< is_same<Iterator,LastIterator> >
+            , apply1<Predicate,Iterator>
+            > type;
+    };
+};
+
+} // namespace aux
+
 template<
-      typename BOOST_MPL_AUX_VOID_SPEC_PARAM(Iterator)
+      typename BOOST_MPL_AUX_VOID_SPEC_PARAM(Sequence)
     , typename BOOST_MPL_AUX_VOID_SPEC_PARAM(State)
     , typename BOOST_MPL_AUX_VOID_SPEC_PARAM(ForwardOp)
     , typename BOOST_MPL_AUX_VOID_SPEC_PARAM(ForwardPredicate)
     , typename BackwardOp = void_
-    , typename BackwardPredicate = always<false_>
+    , typename BackwardPredicate = void_
     >
 struct iter_fold_if
 {
 private:
 
+    typedef typename begin<Sequence>::type first_;
+    typedef typename end<Sequence>::type last_;
+    typedef typename lambda<ForwardOp>::type forward_op_;
+    typedef typename lambda<ForwardPredicate>::type forward_pred_;
+    typedef typename lambda<BackwardOp>::type backward_op_;
+
+    typedef typename apply_if<
+          is_void_<BackwardPredicate>
+        , if_< is_void_<BackwardOp>, always<false_>, always<true_> >
+        , lambda<BackwardPredicate>
+        >::type backward_pred_;
+
 // cwpro8 doesn't like 'cut-off' type here (use typedef instead)
 #if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
     struct result_ :
@@ -48,12 +84,12 @@ private:
     typedef
 #endif
         aux::iter_fold_if_impl<
-          Iterator
+          first_
         , State
-        , typename lambda<ForwardOp>::type
-        , typename lambda<ForwardPredicate>::type
-        , typename lambda<BackwardOp>::type
-        , typename lambda<BackwardPredicate>::type
+        , forward_op_
+        , aux::iter_fold_if_pred< forward_pred_,last_ >
+        , backward_op_
+        , backward_pred_
         >
 #if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
     { };
@@ -71,7 +107,7 @@ public:
     BOOST_MPL_AUX_LAMBDA_SUPPORT(
           6
         , iter_fold_if
-        , (Iterator,State,ForwardOp,ForwardPredicate,BackwardOp,BackwardPredicate)
+        , (Sequence,State,ForwardOp,ForwardPredicate,BackwardOp,BackwardPredicate)
         )
 };